An email address contains the # character. Write a program that takes a word from the keyboard and outputs whether it is an email address based on the presence of the # character. Do not worry about what else is in the word.
import java.util.Scanner;
public class EmailAddress {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print(" Enter a word: " );
String word = input.nextLine();
int count = 0;
for(int i = 0; i < word.length(); i++) {
if(word.charAt(i) == '#')
count++;
}
if(count > 0)
System.out.println("Its an E-mail ");
else
System.out.println("Its not an E-mail ");
}
}
import java.util.Scanner; //Imports the scanner function
public class TestingCode { //standard java input
public static void main(String args[]) { //standard java input
Scanner scan = new Scanner (System.in) ; //asks the user to input the email they would like to find the domain for
System.out.print ( "What is the email? : " );
String email = scan.next(); //scans for the next string
int index = email.indexOf('#') ; //finds the index at which the # is located at and stores it as index
String domain = email.substring (index , email.length() ); //uses the substring function to cut out everything before the # symbol and stores that snippet as variable domain .
System.out.print("The email domain is " + domain ); //displays variable domain
}
}
I don't know why y'all making this code so complicated?!
import java.util.Scanner;
import java.util.*; //I Always import this as a good habit
public class EmailAddress
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.print(" Enter a word: " );
String word = input.nextLine();
if(word.contains('#'))
{
System.out.println("It's an Email");
}
else
{
System.out.println("It's not an Email");
}
}
}
Related
I am new to Java and have a task: Scanner a number of "strangers' " names, then read these names and print "Hello+name" to the console. If number of strangers is zero, then print "Looks empty", if the number is negative, then print "Looks negative to me".
So the input and output to console should look like this:
3
Den
Ken
Mel
Hello, Den
Hello, Ken
Hello, Mel
So I have this code edited from someone with some related task, but it seems I miss something as I am new to Java...
Scanner input = new Scanner(System.in);
System.out.println("Enter the size of an Array");
int num = input.nextInt();
while (num==0) {
System.out.println("Oh, it looks like there is no one here");
break;
} while (num<0) {
System.out.println("Seriously? Why so negative?");
break;
}
String[] numbers = new String[num];
for (int i=0; i< numbers.length;i++) {
System.out.println("Hello, " +input.nextLine());
}
With using do while loop you can ask the number to the user again and again if it is negative number.
import java.util.Scanner;
public class Main
{
public static void main(String[] args) {
int num;
String name;
Scanner scan = new Scanner(System.in);
//The loop asks a number till the number is nonnegative
do{
System.out.print("Please enter the number of strangers: ");
num = scan.nextInt();
if(num<0) {
System.out.println("It cannot be a negative number try again.");
}else if(num==0) {
System.out.println("Oh, it looks like there is no one here");
break;
}else{
String[] strangers = new String[num];
//Takes the names and puts them to the strangers array
for(int i=0;i<num;i++) {
System.out.print("Name " + (i+1) + " : ");
name = scan.next();
strangers[i] = name;
}
//Printing the array
for(int j=0; j<num; j++) {
System.out.println("Hello, " + strangers[j]);
}
break;
}
}while(num<0);
}
}
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter the size of an Array");
int num = input.nextInt();
if(num==0) {
System.out.println("Oh, it looks like there is no one here");
}
else if(num<0) {
System.out.println("Seriously? Why so negative?");
}
else {
String numbers[] = new String[num];
input.nextLine();
for (int i=0; i< num;i++) {
numbers[i]=input.nextLine();
}
for (int i=0; i< numbers.length;i++) {
System.out.println("Hello, " +numbers[i]);
}
}
}
}
This is how your code will look and you'll need to add member function input.nextLine(); to read newline character, so there can't be problem regarding input
I am supposed to make a program that asks users for a list of input. Then, from that list, my program is supposed to pick out the third answer and then print it out. It sounds really simple, but how do I assign numbers to each of the user inputs? Do I even do that? I am a beginner, and thank you so much for your help!
This is the code I have so far:
import java.util.*;
public class MyProgram
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
while(true) {
System.out.println("What do you appreciate in your life or school?");
String ans = scan.nextLine();
if(ans.equals(""))
{
break;
}
}
System.out.println("You said \"" + input3 + "\" as your third answer.");
}
}
You can strore the third input in a variable you initialized bevor the loop.
if there is no third input it prints: ""
import java.util.*;
public class MyProgram
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
int index = 0;
String input3 = "";
while(true) {
System.out.println("What do you appreciate in your life or school?");
String ans = scan.nextLine();
if (index == 2) {
input3 = ans;
}
if(ans.equals("")){
break;
}
index++;
}
System.out.println("You said \"" + input3 + "\" as your third answer.");
}
}
I've been trying to make this program work, have the person write a word in the console and make the console have an output saying if that word is or isn't a palindrome.
package sct;
import java.util.Scanner;
public class Assignment3Problem4 {
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
System.out.println("Enter a a string: ");
String DAWORD = reader.nextLine();
reader.close();
int n = DAWORD.length();
boolean isPalindrome = true;
for (int i = 0; i < n; ++i) {
if (DAWORD.charAt(i) != DAWORD.charAt(n - i - 1)) {
isPalindrome = false;
break;
}
if (isPalindrome)
System.out.println("This word is a palindrome");
else
System.out.println("This word is not a palindrome");
}
}
}
Sadly, this didn't work and the console doesn't let me input a string, can someone find out why and fix the code?
You shouldn't print whether the word is a palindrome (or not) until after the for loop. That's the only issue I had running the posted code.
Scanner reader = new Scanner(System.in);
System.out.println("Enter a a string: ");
String DAWORD = reader.nextLine();
reader.close();
int n = DAWORD.length();
boolean isPalindrome = true;
for (int i = 0; i < n; ++i) {
if (DAWORD.charAt(i) != DAWORD.charAt(n - i - 1)) {
isPalindrome = false;
break;
}
}
if (isPalindrome)
System.out.println("This word is a palindrome");
else
System.out.println("This word is not a palindrome");
You might want to remove reader.close() (as that also closes System.in).
Another approach you could consider is putting your input into a StringBuilder object, reverse it, then check if it equals your input.
Something like:
import java.util.Scanner;
public class StackOverflow {
public static void main(String args[]) {
Scanner reader = new Scanner(System.in);
System.out.println("Enter a string: ");
String DAWORD = reader.nextLine();
reader.close();
if (new StringBuilder(DAWORD).reverse().toString().contentEquals(DAWORD))
System.out.println("This word is a palindrome");
else
System.out.println("This word is not a palindrome");
}
}
Result:
Enter a string:
racecar
This word is a palindrome
You can also use an external apache lang library from here https://mvnrepository.com/artifact/org.apache.commons/commons-lang3/3.7. Then you can use StringUtils.reverse() method which reverses a string and then compare reversed string with the normal one , like so:
import org.apache.commons.lang3.StringUtils;
public class Main4 {
public static void main(String[] args) {
String str = "kajak";
String str2 =StringUtils.reverse(str);
if (str2.equals(str)){
System.out.println("It's a palidrom");
}
else{
System.out.println("Not a palidorm");
}
}
}
Hi I'm trying to write a program that will check a designated file for a number that a user has input, however if the number is not present in the file I want the program to loop back to the beginning, how could I do this?
Here is the mess I've made so far:
import java.util.Scanner;
public class Classtest2 {
public static void main(String[] args) {
// //1. class
Scanner sc = new Scanner(Classtest2.class.getResourceAsStream("trombones.txt"));
Scanner myScanner = new Scanner(System.in);
System.out.println("What number would you like to check for?");
String number = myScanner.nextLine() ;
String keyWord = number, word;
int lineNum = 0;
while(sc.hasNextLine()) {
word = sc.next();
if(word.equals(myScanner.nextLine().trim())) {
System.out.println("The number "+number+ " is there");
break;
} else {
// not found
}
} // main
} // class
all you need to do is take input from user and then check is it exist in file .you shouldn't use myScanner.nextLine().trim() inside while loop because then it waits to get user input every loop time .ones you get a number from user ,you should check it in the file .what you did is get user input and then again wait for user to input value again and again
fixed code
import java.util.Scanner;
public class Classtest2 {
public static void main(String[] args) {
// //1. class
Scanner sc = new Scanner(Classtest2.class.getResourceAsStream("trombones.txt"));
Scanner myScanner = new Scanner(System.in);
System.out.println("What number would you like to check for?");
String number = myScanner.nextLine() ;
int lineNum = 0;
while(sc.hasNextLine()) {
word = sc.next();
if(word.equals(number.trim())) { //here was the problem
System.out.println("The number "+number+ " is there");
return;
} else {
}
}
System.out.println("not found"); // not found
}
the best approach
import java.util.Scanner;
public class Classtest2 {
public static void main(String[] args) {
Scanner myScanner = new Scanner(System.in);
System.out.println("What number would you like to check for?");
String number = myScanner.nextLine();
if(isFound(number)){
System.out.println("The number "+number+ " is there");
}else{
System.out.println("The number "+number+ " doesn't exist");
}
}
public static boolean isFound(String number) {
Scanner sc = new Scanner(Classtest2.class.getResourceAsStream("trombones.txt"));
String word="";
while (sc.hasNextLine()) {
word = sc.next();
if (word.equals(number.trim())) {
return true;
}
}
return false;
}
}
This works for me, hope is useful for you:
package test;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;
public class Classtest2 {
public static void main(String[] args) throws IOException {
File f = new File("trombones.txt");
f.createNewFile();
Scanner myScanner = new Scanner(System.in);
boolean numExiste = menu(new Scanner(f), myScanner);
while (!(numExiste)){
numExiste = menu(new Scanner(f), myScanner);
}
myScanner.close();
}
private static boolean menu(Scanner fileScanner, Scanner myScanner) throws FileNotFoundException{
String word = "";
System.out.println("What number would you like to check for?");
String number = myScanner.nextLine().trim();
while(fileScanner.hasNextLine()){
word = fileScanner.nextLine();
if(word.trim().equals(number)){
System.out.println("The number "+number+ " is there");
return true;
}else{
//Not the number
}
}
System.out.println("The number "+ number+ " is not in the file\n\n");
return false;
}
} // main } // class
This is what I have so far. I want the program to print out the words the user inputs as a sentence. But
I don't know how I get that to happen with the code I have written so far.
ex: if you entered
Hello
World
done
The program should say: "Hello World"
import java.util.Scanner;
public class Chapter3ProblemsSet {
public static void main(String [] args) {
String word = "";
final String SENTINEL = "done";
double count = 0;
String userInput = "";
Scanner in = new Scanner (System.in);
System.out.println("Please enter words: ");
System.out.println("Enter done to finish.");
word = in.next();
do {
word = in.next();
count++;
System.out.print(" "+word);
}
while (!word.equals(SENTINEL));
System.out.println(" "+word);
}
}
What you need it to store it in a variable which is declared outside the loop.
StringBuilder sentence=new StringBuilder();
do {
word = in.nextLine();
count++;
System.out.print(" "+word);
sentence.append(" "+word);
}
while (!word.equals(SENTINEL));
Then for printing use
System.out.println(sentence.toString());
You will need to create an additional string to "collect" all of the words that the user enters. The problem with your original is that you replace 'word' with the word entered. This should do the trick:
import java.util.Scanner;
public class Chapter3ProblemsSet {
public static void main(String [] args) {
String word = "";
String sentence = "";
final String SENTINEL = "done";
double count = 0;
String userInput = "";
Scanner in = new Scanner (System.in);
System.out.println("Please enter words: ");
System.out.println("Enter done to finish.");
word = in.next();
do {
word = in.next();
count++;
sentence += " " + word;
System.out.print(" "+word);
}
while (!word.equals(SENTINEL));
System.out.println(" "+sentence);
}
}
You can read it by pieces and put them together using a StringBuffer - http://docs.oracle.com/javase/7/docs/api/java/lang/StringBuffer.html
StringBuffer sb = new StringBuffer();
do {
sb.append( in.next() );
count++;
}
while (!word.equals(SENTINEL));