INPUT : 123ABC458
OUTPUT : 321ABC854
public static void main(String []args){
String str="123ABC564";
int count=0;
int ans=0;
int firstindex=0;
char[] ch = str.toCharArray();
for(int i=0;i<ch.length;i++){
if(Character.isDigit(ch[i])){
if(ans==0){
firstindex=i;
}
count++;
}
else{
int lastindex=count+firstindex-1;
while(firstindex<lastindex){
char temp=ch[firstindex];
ch[firstindex]=ch[lastindex];
ch[lastindex]=temp;
firstindex++;
lastindex--;
}
ans=0;
count=0;
firstindex=0;
}
}
for (char c : ch){
System.out.print(c);
}
}
}
Can anyone tell me what's wrong with this code
The output which I am getting using this code is 12BA3C564
You can use the Java regex API and StringBuilder to solve it easily. The regex, \d+ specifies one or more digits. Using the Java regex API, you find the numbers, their start position and the end positions which you can use to build the required string.
Demo:
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Main {
public static void main(String[] args) {
// Tests
String[] samples = { "123ABC458", "123ABC458XYZ", "123ABC458XYZ367", "ABC123XYZ", "ABC123XYZ" };
for (String s : samples)
System.out.println(numbersInverted(s));
}
static String numbersInverted(String str) {
StringBuilder sb = new StringBuilder();
Matcher matcher = Pattern.compile("\\d+").matcher(str);
int lastInitialPos = 0;
while (matcher.find()) {
int start = matcher.start();
String inverted = new StringBuilder(matcher.group()).reverse().toString();
sb.append(str.substring(lastInitialPos, start)).append(inverted);
lastInitialPos = matcher.end();
}
if (sb.length() == 0) // If no number was found
return str;
else
return sb.append(str.substring(lastInitialPos)).toString();
}
}
Output:
321ABC854
321ABC854XYZ
321ABC854XYZ763
ABC321XYZ
ABC321XYZ
ONLINE DEMO
Here is a concise version using string splitting:
String input = "123ABC458";
String[] parts = input.split("(?<=\\D)(?=\\d)|(?<=\\d)(?=\\D)");
StringBuilder sb = new StringBuilder();
for (String part : parts) {
if (part.matches("\\d+")) {
StringBuilder num = new StringBuilder(part);
sb.append(num.reverse());
}
else {
sb.append(part);
}
}
System.out.println(sb.toString()); // 321ABC854
The splitting operation used above generates a string array of either numbers or letters. Then, we iterate that array and selectively reverse the number strings using StringBuilder#reverse.
This task can be implemented without regular expressions, splitting the input string into substring etc. merely with the help of StringBuilder::insert(int offset, char c) and StringBuilder::append(char c) using simple index calculation for insert:
public static String revertDigits(String str) {
if (str == null || str.isEmpty()) {
return str;
}
StringBuilder sb = new StringBuilder(str.length());
for (int i = 0, j = 0, n = str.length(); i < n; i++) {
char c = str.charAt(i);
if (Character.isDigit(c)) {
sb.insert(j, c); // append in "reverse" mode
} else {
sb.append(c);
j = i + 1; // store the last position of a non-digit
}
}
return sb.toString();
}
Test:
String str="123ABC564";
System.out.println(str + '\n' + revertDigits(str));
Output
123ABC564
321ABC465
Can anyone tell me what's wrong with this code
I believe I have spotted two bugs in your code:
You are never setting ans to anything else than 0. So your if condition ans==0 will always be true. If I have understood the purpose of that variable correctly, you may want to replace it with a boolean called something like insideNumber and set it to true when you detect a digit and to false when you detect that a char is not a digit. Your if statement then becomes if (insideNumber) …
You don’t take a number at the end of your string into account. You can check this statement by appending a letter to your string and see that 564 will then be reversed into 465. To reverse a trailing number correctly: after your loop again check whether you were inside a number, and if so, reverse the last number from firstindex up to the end of the string.
You can get all the numbers from the string as the first move, and then replace the input with the reversed string of the numbers. Example:
public static void main(String[] args)
{
String input = "123ABC458";
Matcher m = Pattern.compile("\\d+").matcher(input);
while(m.find())
input = input.replace(m.group(), new StringBuilder(m.group()).reverse());
System.out.println(input);
}
As an alternative solution, from Java 9 you could also make use of Matcher#replaceAll and reverse every match for 1 or more digits.
String result = Pattern.compile("\\d+")
.matcher("123ABC458")
.replaceAll(m -> new StringBuilder(m.group()).reverse().toString());
System.out.println(result);
Output
321ABC854
Java demo
I am creating a CamelCase function in Java that takes a string this_is_a_sentence and returns ThisIsASentence My main problem comes with handeling the different characters in the string.
So far I have:
import java.util.Scanner;
public class Main{
public static String camelCaser(String str){
char[] strChr = str.toCharArray();
strChr[0] = strChr[0].toUpperCase;
for(int i = 0; i < strChr.length; i++){
if (strChr[i] == '_'){
strChr[i] = strChr[i+1].toUpperCase;
strChr[i+1] = "";
}
}
String newStr = new String(strChr);
return newStr;
}
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("String: ");
String str = input.next();
System.out.printf("Converting: %s into %s", str, camelCaser(str));
}
}
My main problems seems to be that you can not alter individual characters the same way that I am used to in C. I have read that you can use a class called Character but I cant figure out how to use it. The Java documentation on the matter https://docs.oracle.com/javase/7/docs/api/java/lang/Character.html did not help me either.
I changed around a bit of your logic to make this work. The easiest thing to make it work was to search the string for _, and then capitalize the following letter. After that, take the resulting string and remove all the _'s. It ended up like this:
import java.util.Scanner;
public class Caser{
public static String camelCaser(String str){
char[] strChr = str.toCharArray();
strChr[0] = Character.toUpperCase(strChr[0]);
for(int i = 0; i < strChr.length; i++) if (strChr[i] == '_') strChr[i+1] = Character.toUpperCase(strChr[i+1]);
String reply = new String(strChr);
reply = reply.replace("_", "");
return reply;
}
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("String: ");
String str = input.next();
System.out.printf("Converting: %s into %s", str, camelCaser(str));
}
}
EDIT:
What does String reply = new String(strChr); do?
This creates a new variable named reply. The variable is a String. new String(strChr) is a helper that the String class has whereby you can give it a char[] and it will automatically turn it into a String.
What does reply = reply.replace("_", ""); do?
.replace(String, String) is a String method that will search said string (in this case, reply) and will search for all instances of _ and when it finds them it will replace it with an empty String (in this case, it is blank "").
This code has several problems. First, toUpperCase() cannot be used on a char, you'd need to call Character.toUpperCase(character). Second, strChar[i+1]=""; does not compile, as "" is the empty String, strChar is a array of char.
I'd do something like this: first, I would split the string by "_" if you're sure you only want this as your separating character using String[] words = str.split("_"). Then, I would create a new String which will be the result String (let's call it res). After that, I would loop over all elements in words, make the first character upper case, add it to res and add all the other characters of the current element to res.
So, it would look like this:
public static String camelCaser(String str){
String[] words = str.split("_"); // split str by _
String res = ""; // result string
for(String word : words) {
// first check, if words is empty
if(!word.isEmpty()) {
// add first character upper case
res += Character.toUpperCase(word.charAt(0));
// add remaining characters as they are, if any
if(word.length() > 1) {
res += word.substring(1);
}
}
}
return res;
}
You would need to do something like Character.toUpperCase(strChr[0]); to convert a character in your array to uppercase.
Use Character.toUpperCase(char).
public class Main{
public static String camelCaser(String str){
char[] strChr = str.toCharArray();
strChr[0] = Character.toUpperCase(strChr[0]);
for(int i = 0; i < strChr.length; i++){
if (strChr[i] == '_'){
strChr[i] = Character.toUpperCase(strChr[i+1]);
strChr[i+1] = Character.valueOf('\u0000') ;
}
}
String newStr = new String(strChr);
return newStr;
}
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("String: ");
String str = input.next();
System.out.printf("Converting: %s into %s", str, camelCaser(str));
}
}
I'm trying to create a palindrome tester program for my AP Java class and I need to remove the white spaces in my code completely but it's not letting me do so.
import java.util.Scanner;
public class Palin{
public static boolean isPalindrome(String stringToTest) {
String workingCopy = removeJunk(stringToTest);
String reversedCopy = reverse(workingCopy);
return reversedCopy.equalsIgnoreCase(workingCopy);
}
public static String removeJunk(String string) {
int i, len = string.length();
StringBuffer dest = new StringBuffer(len);
char c;
for (i = (len - 1); i >= 0; i-=1) {
c = string.charAt(i);
if (Character.isLetterOrDigit(c))
{
dest.append(c);
}
}
return dest.toString();
}
public static String reverse(String string) {
StringBuffer sb = new StringBuffer(string);
return sb.reverse().toString();
}
public static void main(String[] args) {
System.out.print("Enter Palindrome: ");
Scanner sc = new Scanner(System.in);
String string = sc.next();
String str = string;
String space = "";
String result = str.replaceAll("\\W", space);
System.out.println(result);
System.out.println();
System.out.println("Testing palindrome:");
System.out.println(" " + string);
System.out.println();
if (isPalindrome(result)) {
System.out.println("It's a palindrome!");
} else {
System.out.println("Not a palindrome!");
}
System.out.println();
}
}
Any help would be greatly appreciated.
Seems like your code is fine except for the following. You are using
String string = sc.next();
which will not read the whole line of input, hence you will lose part of the text. I think you should use the following instead of that line.
String string = sc.nextLine();
If you just want to remove the beginning and ending whitespace, you can use the built in function trim(), e.g. " abcd ".trim() is "abcd"
If you want to remove it everywhere, you can use the replaceAll() method with the whitespace class as the parameter, e.g. " abcd ".replaceAll("\W","").
Use a StringTokenizer to remove " "
StringTokenizer st = new StringTokenizer(string," ",false);
String t="";
while (st.hasMoreElements()) t += st.nextElement();
String result = t;
System.out.println(result);
I haven't actually tesed this, but have you considered the String.replaceAll(String regex, String replacement) method?
public static String removeJunk (String string) {
return string.replaceAll (" ", "");
}
Another thing to look out for is that while removing all non-digit/alpha characters removeJunk also reverses the string (it starts from the end and then appends one character at a time).
So after reversing it again (in reverse) you are left with the original and it will always claim that the given string is a palindrome.
You should use the String replace(char oldChar, char newChar) method.
Although the name suggests that only the first occurrence will be replaced, fact is that all occurrences will be replaced. The advantage of this method is that it won't use regular expressions, thus is more efficient.
So give a try to string.replace(' ', '');
I have a string, with characters a-z, A-Z, 0-9, (, ), +, -, etc.
I want to find every word within that string and replace it with the same word with 'word' (single quotes added). Words in that string can be preceded/followed by "(", ")", and spaces.
How do I go about doing that?
Input:
(Movie + 2000)
Output:
('Movie' + '2000')
Keep it simple! This does what you need:
String input = "(Movie + 2000)";
input.replaceAll("\\b", "'");
// Outputs "('Movie' + '2000')"
This uses the regex \b, which is a "word boundary". What could be simpler?
As stated in the comments, regex is a good way to go:
String input = "(Movie + 2000)";
input = input.replaceAll("[A-Za-z0-9]+", "'$0'");
You don't give a precise defition of 'word', so I assume it is any combination of letters and numbers.
EDIT OK, thanks to #Buhb for explaining why this solution is not the best one. Better solution was given by #Bohemian.
public class Main {
/**
* #param args
*/
public static void main(String[] args) {
String str1 = "Hello string";
String str2 = "str";
System.out.println(replace(str1, str2, "'" + str2 + "'"));
}
static String replace(String str, String pattern, String replace) {
int s = 0;
int e = 0;
StringBuffer result = new StringBuffer();
while ((e = str.indexOf(pattern, s)) >= 0) {
result.append(str.substring(s, e));
result.append(replace);
s = e + pattern.length();
}
result.append(str.substring(s));
return result.toString();
}
}
Output: Hello 'str'ing
WBR
It makes sense to return string only if a replacement took place, see below:
if(s>0)
return result.toString();
else
return null;
Is there a function built into Java that capitalizes the first character of each word in a String, and does not affect the others?
Examples:
jon skeet -> Jon Skeet
miles o'Brien -> Miles O'Brien (B remains capital, this rules out Title Case)
old mcdonald -> Old Mcdonald*
*(Old McDonald would be find too, but I don't expect it to be THAT smart.)
A quick look at the Java String Documentation reveals only toUpperCase() and toLowerCase(), which of course do not provide the desired behavior. Naturally, Google results are dominated by those two functions. It seems like a wheel that must have been invented already, so it couldn't hurt to ask so I can use it in the future.
WordUtils.capitalize(str) (from apache commons-text)
(Note: if you need "fOO BAr" to become "Foo Bar", then use capitalizeFully(..) instead)
If you're only worried about the first letter of the first word being capitalized:
private String capitalize(final String line) {
return Character.toUpperCase(line.charAt(0)) + line.substring(1);
}
The following method converts all the letters into upper/lower case, depending on their position near a space or other special chars.
public static String capitalizeString(String string) {
char[] chars = string.toLowerCase().toCharArray();
boolean found = false;
for (int i = 0; i < chars.length; i++) {
if (!found && Character.isLetter(chars[i])) {
chars[i] = Character.toUpperCase(chars[i]);
found = true;
} else if (Character.isWhitespace(chars[i]) || chars[i]=='.' || chars[i]=='\'') { // You can add other chars here
found = false;
}
}
return String.valueOf(chars);
}
Try this very simple way
example givenString="ram is good boy"
public static String toTitleCase(String givenString) {
String[] arr = givenString.split(" ");
StringBuffer sb = new StringBuffer();
for (int i = 0; i < arr.length; i++) {
sb.append(Character.toUpperCase(arr[i].charAt(0)))
.append(arr[i].substring(1)).append(" ");
}
return sb.toString().trim();
}
Output will be: Ram Is Good Boy
I made a solution in Java 8 that is IMHO more readable.
public String firstLetterCapitalWithSingleSpace(final String words) {
return Stream.of(words.trim().split("\\s"))
.filter(word -> word.length() > 0)
.map(word -> word.substring(0, 1).toUpperCase() + word.substring(1))
.collect(Collectors.joining(" "));
}
The Gist for this solution can be found here: https://gist.github.com/Hylke1982/166a792313c5e2df9d31
String toBeCapped = "i want this sentence capitalized";
String[] tokens = toBeCapped.split("\\s");
toBeCapped = "";
for(int i = 0; i < tokens.length; i++){
char capLetter = Character.toUpperCase(tokens[i].charAt(0));
toBeCapped += " " + capLetter + tokens[i].substring(1);
}
toBeCapped = toBeCapped.trim();
I've written a small Class to capitalize all the words in a String.
Optional multiple delimiters, each one with its behavior (capitalize before, after, or both, to handle cases like O'Brian);
Optional Locale;
Don't breaks with Surrogate Pairs.
LIVE DEMO
Output:
====================================
SIMPLE USAGE
====================================
Source: cApItAlIzE this string after WHITE SPACES
Output: Capitalize This String After White Spaces
====================================
SINGLE CUSTOM-DELIMITER USAGE
====================================
Source: capitalize this string ONLY before'and''after'''APEX
Output: Capitalize this string only beforE'AnD''AfteR'''Apex
====================================
MULTIPLE CUSTOM-DELIMITER USAGE
====================================
Source: capitalize this string AFTER SPACES, BEFORE'APEX, and #AFTER AND BEFORE# NUMBER SIGN (#)
Output: Capitalize This String After Spaces, BeforE'apex, And #After And BeforE# Number Sign (#)
====================================
SIMPLE USAGE WITH CUSTOM LOCALE
====================================
Source: Uniforming the first and last vowels (different kind of 'i's) of the Turkish word D[İ]YARBAK[I]R (DİYARBAKIR)
Output: Uniforming The First And Last Vowels (different Kind Of 'i's) Of The Turkish Word D[i]yarbak[i]r (diyarbakir)
====================================
SIMPLE USAGE WITH A SURROGATE PAIR
====================================
Source: ab 𐐂c de à
Output: Ab 𐐪c De À
Note: first letter will always be capitalized (edit the source if you don't want that).
Please share your comments and help me to found bugs or to improve the code...
Code:
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
public class WordsCapitalizer {
public static String capitalizeEveryWord(String source) {
return capitalizeEveryWord(source,null,null);
}
public static String capitalizeEveryWord(String source, Locale locale) {
return capitalizeEveryWord(source,null,locale);
}
public static String capitalizeEveryWord(String source, List<Delimiter> delimiters, Locale locale) {
char[] chars;
if (delimiters == null || delimiters.size() == 0)
delimiters = getDefaultDelimiters();
// If Locale specified, i18n toLowerCase is executed, to handle specific behaviors (eg. Turkish dotted and dotless 'i')
if (locale!=null)
chars = source.toLowerCase(locale).toCharArray();
else
chars = source.toLowerCase().toCharArray();
// First charachter ALWAYS capitalized, if it is a Letter.
if (chars.length>0 && Character.isLetter(chars[0]) && !isSurrogate(chars[0])){
chars[0] = Character.toUpperCase(chars[0]);
}
for (int i = 0; i < chars.length; i++) {
if (!isSurrogate(chars[i]) && !Character.isLetter(chars[i])) {
// Current char is not a Letter; gonna check if it is a delimitrer.
for (Delimiter delimiter : delimiters){
if (delimiter.getDelimiter()==chars[i]){
// Delimiter found, applying rules...
if (delimiter.capitalizeBefore() && i>0
&& Character.isLetter(chars[i-1]) && !isSurrogate(chars[i-1]))
{ // previous character is a Letter and I have to capitalize it
chars[i-1] = Character.toUpperCase(chars[i-1]);
}
if (delimiter.capitalizeAfter() && i<chars.length-1
&& Character.isLetter(chars[i+1]) && !isSurrogate(chars[i+1]))
{ // next character is a Letter and I have to capitalize it
chars[i+1] = Character.toUpperCase(chars[i+1]);
}
break;
}
}
}
}
return String.valueOf(chars);
}
private static boolean isSurrogate(char chr){
// Check if the current character is part of an UTF-16 Surrogate Pair.
// Note: not validating the pair, just used to bypass (any found part of) it.
return (Character.isHighSurrogate(chr) || Character.isLowSurrogate(chr));
}
private static List<Delimiter> getDefaultDelimiters(){
// If no delimiter specified, "Capitalize after space" rule is set by default.
List<Delimiter> delimiters = new ArrayList<Delimiter>();
delimiters.add(new Delimiter(Behavior.CAPITALIZE_AFTER_MARKER, ' '));
return delimiters;
}
public static class Delimiter {
private Behavior behavior;
private char delimiter;
public Delimiter(Behavior behavior, char delimiter) {
super();
this.behavior = behavior;
this.delimiter = delimiter;
}
public boolean capitalizeBefore(){
return (behavior.equals(Behavior.CAPITALIZE_BEFORE_MARKER)
|| behavior.equals(Behavior.CAPITALIZE_BEFORE_AND_AFTER_MARKER));
}
public boolean capitalizeAfter(){
return (behavior.equals(Behavior.CAPITALIZE_AFTER_MARKER)
|| behavior.equals(Behavior.CAPITALIZE_BEFORE_AND_AFTER_MARKER));
}
public char getDelimiter() {
return delimiter;
}
}
public static enum Behavior {
CAPITALIZE_AFTER_MARKER(0),
CAPITALIZE_BEFORE_MARKER(1),
CAPITALIZE_BEFORE_AND_AFTER_MARKER(2);
private int value;
private Behavior(int value) {
this.value = value;
}
public int getValue() {
return value;
}
}
Using org.apache.commons.lang.StringUtils makes it very simple.
capitalizeStr = StringUtils.capitalize(str);
From Java 9+
you can use String::replaceAll like this :
public static void upperCaseAllFirstCharacter(String text) {
String regex = "\\b(.)(.*?)\\b";
String result = Pattern.compile(regex).matcher(text).replaceAll(
matche -> matche.group(1).toUpperCase() + matche.group(2)
);
System.out.println(result);
}
Example :
upperCaseAllFirstCharacter("hello this is Just a test");
Outputs
Hello This Is Just A Test
With this simple code:
String example="hello";
example=example.substring(0,1).toUpperCase()+example.substring(1, example.length());
System.out.println(example);
Result: Hello
I'm using the following function. I think it is faster in performance.
public static String capitalize(String text){
String c = (text != null)? text.trim() : "";
String[] words = c.split(" ");
String result = "";
for(String w : words){
result += (w.length() > 1? w.substring(0, 1).toUpperCase(Locale.US) + w.substring(1, w.length()).toLowerCase(Locale.US) : w) + " ";
}
return result.trim();
}
Use the Split method to split your string into words, then use the built in string functions to capitalize each word, then append together.
Pseudo-code (ish)
string = "the sentence you want to apply caps to";
words = string.split(" ")
string = ""
for(String w: words)
//This line is an easy way to capitalize a word
word = word.toUpperCase().replace(word.substring(1), word.substring(1).toLowerCase())
string += word
In the end string looks something like
"The Sentence You Want To Apply Caps To"
This might be useful if you need to capitalize titles. It capitalizes each substring delimited by " ", except for specified strings such as "a" or "the". I haven't ran it yet because it's late, should be fine though. Uses Apache Commons StringUtils.join() at one point. You can substitute it with a simple loop if you wish.
private static String capitalize(String string) {
if (string == null) return null;
String[] wordArray = string.split(" "); // Split string to analyze word by word.
int i = 0;
lowercase:
for (String word : wordArray) {
if (word != wordArray[0]) { // First word always in capital
String [] lowercaseWords = {"a", "an", "as", "and", "although", "at", "because", "but", "by", "for", "in", "nor", "of", "on", "or", "so", "the", "to", "up", "yet"};
for (String word2 : lowercaseWords) {
if (word.equals(word2)) {
wordArray[i] = word;
i++;
continue lowercase;
}
}
}
char[] characterArray = word.toCharArray();
characterArray[0] = Character.toTitleCase(characterArray[0]);
wordArray[i] = new String(characterArray);
i++;
}
return StringUtils.join(wordArray, " "); // Re-join string
}
public static String toTitleCase(String word){
return Character.toUpperCase(word.charAt(0)) + word.substring(1);
}
public static void main(String[] args){
String phrase = "this is to be title cased";
String[] splitPhrase = phrase.split(" ");
String result = "";
for(String word: splitPhrase){
result += toTitleCase(word) + " ";
}
System.out.println(result.trim());
}
1. Java 8 Streams
public static String capitalizeAll(String str) {
if (str == null || str.isEmpty()) {
return str;
}
return Arrays.stream(str.split("\\s+"))
.map(t -> t.substring(0, 1).toUpperCase() + t.substring(1))
.collect(Collectors.joining(" "));
}
Examples:
System.out.println(capitalizeAll("jon skeet")); // Jon Skeet
System.out.println(capitalizeAll("miles o'Brien")); // Miles O'Brien
System.out.println(capitalizeAll("old mcdonald")); // Old Mcdonald
System.out.println(capitalizeAll(null)); // null
For foo bAR to Foo Bar, replace the map() method with the following:
.map(t -> t.substring(0, 1).toUpperCase() + t.substring(1).toLowerCase())
2. String.replaceAll() (Java 9+)
ublic static String capitalizeAll(String str) {
if (str == null || str.isEmpty()) {
return str;
}
return Pattern.compile("\\b(.)(.*?)\\b")
.matcher(str)
.replaceAll(match -> match.group(1).toUpperCase() + match.group(2));
}
Examples:
System.out.println(capitalizeAll("12 ways to learn java")); // 12 Ways To Learn Java
System.out.println(capitalizeAll("i am atta")); // I Am Atta
System.out.println(capitalizeAll(null)); // null
3. Apache Commons Text
System.out.println(WordUtils.capitalize("love is everywhere")); // Love Is Everywhere
System.out.println(WordUtils.capitalize("sky, sky, blue sky!")); // Sky, Sky, Blue Sky!
System.out.println(WordUtils.capitalize(null)); // null
For titlecase:
System.out.println(WordUtils.capitalizeFully("fOO bAR")); // Foo Bar
System.out.println(WordUtils.capitalizeFully("sKy is BLUE!")); // Sky Is Blue!
For details, checkout this tutorial.
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the sentence : ");
try
{
String str = br.readLine();
char[] str1 = new char[str.length()];
for(int i=0; i<str.length(); i++)
{
str1[i] = Character.toLowerCase(str.charAt(i));
}
str1[0] = Character.toUpperCase(str1[0]);
for(int i=0;i<str.length();i++)
{
if(str1[i] == ' ')
{
str1[i+1] = Character.toUpperCase(str1[i+1]);
}
System.out.print(str1[i]);
}
}
catch(Exception e)
{
System.err.println("Error: " + e.getMessage());
}
I decided to add one more solution for capitalizing words in a string:
words are defined here as adjacent letter-or-digit characters;
surrogate pairs are provided as well;
the code has been optimized for performance; and
it is still compact.
Function:
public static String capitalize(String string) {
final int sl = string.length();
final StringBuilder sb = new StringBuilder(sl);
boolean lod = false;
for(int s = 0; s < sl; s++) {
final int cp = string.codePointAt(s);
sb.appendCodePoint(lod ? Character.toLowerCase(cp) : Character.toUpperCase(cp));
lod = Character.isLetterOrDigit(cp);
if(!Character.isBmpCodePoint(cp)) s++;
}
return sb.toString();
}
Example call:
System.out.println(capitalize("An à la carte StRiNg. Surrogate pairs: 𐐪𐐪."));
Result:
An À La Carte String. Surrogate Pairs: 𐐂𐐪.
Use:
String text = "jon skeet, miles o'brien, old mcdonald";
Pattern pattern = Pattern.compile("\\b([a-z])([\\w]*)");
Matcher matcher = pattern.matcher(text);
StringBuffer buffer = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(buffer, matcher.group(1).toUpperCase() + matcher.group(2));
}
String capitalized = matcher.appendTail(buffer).toString();
System.out.println(capitalized);
There are many way to convert the first letter of the first word being capitalized. I have an idea. It's very simple:
public String capitalize(String str){
/* The first thing we do is remove whitespace from string */
String c = str.replaceAll("\\s+", " ");
String s = c.trim();
String l = "";
for(int i = 0; i < s.length(); i++){
if(i == 0){ /* Uppercase the first letter in strings */
l += s.toUpperCase().charAt(i);
i++; /* To i = i + 1 because we don't need to add
value i = 0 into string l */
}
l += s.charAt(i);
if(s.charAt(i) == 32){ /* If we meet whitespace (32 in ASCII Code is whitespace) */
l += s.toUpperCase().charAt(i+1); /* Uppercase the letter after whitespace */
i++; /* Yo i = i + 1 because we don't need to add
value whitespace into string l */
}
}
return l;
}
package com.test;
/**
* #author Prasanth Pillai
* #date 01-Feb-2012
* #description : Below is the test class details
*
* inputs a String from a user. Expect the String to contain spaces and alphanumeric characters only.
* capitalizes all first letters of the words in the given String.
* preserves all other characters (including spaces) in the String.
* displays the result to the user.
*
* Approach : I have followed a simple approach. However there are many string utilities available
* for the same purpose. Example : WordUtils.capitalize(str) (from apache commons-lang)
*
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Test {
public static void main(String[] args) throws IOException{
System.out.println("Input String :\n");
InputStreamReader converter = new InputStreamReader(System.in);
BufferedReader in = new BufferedReader(converter);
String inputString = in.readLine();
int length = inputString.length();
StringBuffer newStr = new StringBuffer(0);
int i = 0;
int k = 0;
/* This is a simple approach
* step 1: scan through the input string
* step 2: capitalize the first letter of each word in string
* The integer k, is used as a value to determine whether the
* letter is the first letter in each word in the string.
*/
while( i < length){
if (Character.isLetter(inputString.charAt(i))){
if ( k == 0){
newStr = newStr.append(Character.toUpperCase(inputString.charAt(i)));
k = 2;
}//this else loop is to avoid repeatation of the first letter in output string
else {
newStr = newStr.append(inputString.charAt(i));
}
} // for the letters which are not first letter, simply append to the output string.
else {
newStr = newStr.append(inputString.charAt(i));
k=0;
}
i+=1;
}
System.out.println("new String ->"+newStr);
}
}
Here is a simple function
public static String capEachWord(String source){
String result = "";
String[] splitString = source.split(" ");
for(String target : splitString){
result += Character.toUpperCase(target.charAt(0))
+ target.substring(1) + " ";
}
return result.trim();
}
This is just another way of doing it:
private String capitalize(String line)
{
StringTokenizer token =new StringTokenizer(line);
String CapLine="";
while(token.hasMoreTokens())
{
String tok = token.nextToken().toString();
CapLine += Character.toUpperCase(tok.charAt(0))+ tok.substring(1)+" ";
}
return CapLine.substring(0,CapLine.length()-1);
}
Reusable method for intiCap:
public class YarlagaddaSireeshTest{
public static void main(String[] args) {
String FinalStringIs = "";
String testNames = "sireesh yarlagadda test";
String[] name = testNames.split("\\s");
for(String nameIs :name){
FinalStringIs += getIntiCapString(nameIs) + ",";
}
System.out.println("Final Result "+ FinalStringIs);
}
public static String getIntiCapString(String param) {
if(param != null && param.length()>0){
char[] charArray = param.toCharArray();
charArray[0] = Character.toUpperCase(charArray[0]);
return new String(charArray);
}
else {
return "";
}
}
}
Here is my solution.
I ran across this problem tonight and decided to search it. I found an answer by Neelam Singh that was almost there, so I decided to fix the issue (broke on empty strings) and caused a system crash.
The method you are looking for is named capString(String s) below.
It turns "It's only 5am here" into "It's Only 5am Here".
The code is pretty well commented, so enjoy.
package com.lincolnwdaniel.interactivestory.model;
public class StringS {
/**
* #param s is a string of any length, ideally only one word
* #return a capitalized string.
* only the first letter of the string is made to uppercase
*/
public static String capSingleWord(String s) {
if(s.isEmpty() || s.length()<2) {
return Character.toUpperCase(s.charAt(0))+"";
}
else {
return Character.toUpperCase(s.charAt(0)) + s.substring(1);
}
}
/**
*
* #param s is a string of any length
* #return a title cased string.
* All first letter of each word is made to uppercase
*/
public static String capString(String s) {
// Check if the string is empty, if it is, return it immediately
if(s.isEmpty()){
return s;
}
// Split string on space and create array of words
String[] arr = s.split(" ");
// Create a string buffer to hold the new capitalized string
StringBuffer sb = new StringBuffer();
// Check if the array is empty (would be caused by the passage of s as an empty string [i.g "" or " "],
// If it is, return the original string immediately
if( arr.length < 1 ){
return s;
}
for (int i = 0; i < arr.length; i++) {
sb.append(Character.toUpperCase(arr[i].charAt(0)))
.append(arr[i].substring(1)).append(" ");
}
return sb.toString().trim();
}
}
Here we go for perfect first char capitalization of word
public static void main(String[] args) {
String input ="my name is ranjan";
String[] inputArr = input.split(" ");
for(String word : inputArr) {
System.out.println(word.substring(0, 1).toUpperCase()+word.substring(1,word.length()));
}
}
}
//Output : My Name Is Ranjan
For those of you using Velocity in your MVC, you can use the capitalizeFirstLetter() method from the StringUtils class.
String s="hi dude i want apple";
s = s.replaceAll("\\s+"," ");
String[] split = s.split(" ");
s="";
for (int i = 0; i < split.length; i++) {
split[i]=Character.toUpperCase(split[i].charAt(0))+split[i].substring(1);
s+=split[i]+" ";
System.out.println(split[i]);
}
System.out.println(s);
package corejava.string.intern;
import java.io.DataInputStream;
import java.util.ArrayList;
/*
* wap to accept only 3 sentences and convert first character of each word into upper case
*/
public class Accept3Lines_FirstCharUppercase {
static String line;
static String words[];
static ArrayList<String> list=new ArrayList<String>();
/**
* #param args
*/
public static void main(String[] args) throws java.lang.Exception{
DataInputStream read=new DataInputStream(System.in);
System.out.println("Enter only three sentences");
int i=0;
while((line=read.readLine())!=null){
method(line); //main logic of the code
if((i++)==2){
break;
}
}
display();
System.out.println("\n End of the program");
}
/*
* this will display all the elements in an array
*/
public static void display(){
for(String display:list){
System.out.println(display);
}
}
/*
* this divide the line of string into words
* and first char of the each word is converted to upper case
* and to an array list
*/
public static void method(String lineParam){
words=line.split("\\s");
for(String s:words){
String result=s.substring(0,1).toUpperCase()+s.substring(1);
list.add(result);
}
}
}
If you prefer Guava...
String myString = ...;
String capWords = Joiner.on(' ').join(Iterables.transform(Splitter.on(' ').omitEmptyStrings().split(myString), new Function<String, String>() {
public String apply(String input) {
return Character.toUpperCase(input.charAt(0)) + input.substring(1);
}
}));
String toUpperCaseFirstLetterOnly(String str) {
String[] words = str.split(" ");
StringBuilder ret = new StringBuilder();
for(int i = 0; i < words.length; i++) {
ret.append(Character.toUpperCase(words[i].charAt(0)));
ret.append(words[i].substring(1));
if(i < words.length - 1) {
ret.append(' ');
}
}
return ret.toString();
}