Develop Reference

Convert a string into a multidimensional arrays with different lengths

I need to execute by command line a code that will provide a multidimensional array with elements with not necessarily equal lengths.
The execution string is bellow:
start /wait java -jar testMSMWithIndex.jar Foursquare_weather_day_root-type_type 0,1,2-4
I'm considering to pass the parameter 0,1,2-4 and then convert it in a multidimensional array with elements of different lengths in this case, i.e. {{0}, {1}, {2, 4}}.
Note that {{0, null}, {1, null}, {2, 4}} does not work to my problem.
Do you guys know how to develop a method or even get directly as an array from args?
I really appreciate any help you can provide.

It's doubtful that anything already exists to do this for you, so you'll have to parse the string for yourself. Something like this would do it:
public static int[][] parseRaggedArrayFromString(String s)
throws NumberFormatException {
String[] ss = s.split(",");
int[][] result = new int[ss.length][];
for (int i = 0; i < ss.length; ++i) {
if (!ss[i].contains("-")) {
result[i] = new int[1];
result[i][0] = Integer.parseInt(ss[i]);
} else {
String[] range = ss[i].split("-", 2);
int lo = Integer.parseInt(range[0]);
int hi = Integer.parseInt(range[1]);
int size = hi - lo + 1;
result[i] = new int[size > 0 ? size : 1];
int j = 0;
do {
result[i][j] = lo;
++lo;
++j;
} while (lo <= hi);
}
}
return result;
}

It's basically a split on , and -. From there is just handling the data. Comments in the code.
/**
* #author sedj601
*/
public class Main {
public static void main(String[] args) {
String input = "0,1,2-3";
String[] firstArray = input.split(",");//Split on ,.
String[][] outputArray = new String[firstArray.length][];//The array that will be holding the output
//Used to process the firstArray
for (int i = 0; i < firstArray.length; i++) {
if (firstArray[i].length() > 1) {//If the lenght is greater than one. split on -.
String[] secondArray = firstArray[i].split("-");
//Subtract the two numbers and add one to get the lenght of the array that will hold these values
int arrayLength = Integer.parseInt(secondArray[1]) - Integer.parseInt(secondArray[0]) + 1;
String[] tempArray = new String[arrayLength];
int increment = 0;//Keeps up with the tempArray index.
//loop from the first number to the last number inclusively.
for (int t = Integer.parseInt(secondArray[0]); t <= Integer.parseInt(secondArray[1]); t++) {
tempArray[increment++] = Integer.toString(t);//Add the data to the array.
}
outputArray[i] = tempArray;//Add the array to the output array.
} else {//If the lenght is 1, creat an array and add the current data.
String[] tempArray = new String[1];
tempArray[0] = firstArray[i];
outputArray[i] = tempArray;
}
}
//Print the output.
for (String[] x : outputArray) {
for (String y : x) {
System.out.print(y + " ");
}
System.out.println();
}
}
}
Output:
--- exec-maven-plugin:1.5.0:exec (default-cli) # JavaTestingGround ---
0
1
2 3
------------------------------------------------------------------------
BUILD SUCCESS
------------------------------------------------------------------------
Total time: 1.194 s
Finished at: 2021-01-08T00:08:15-06:00
------------------------------------------------------------------------

I really think that's possible when you create an array of type Object .(not a good idea) Since multi-D arrays can only hold arrays of same length (int[][]). Then you create and retrieve values from array by casting...
I am trying here to be creative and adopt to your requirements..
public class x {
public static void main(String[] args) {
Object[] arguments = new Object[args.length];
// Then make a loop to capture arguments in array..
// or add manually
arguments[0] = new String[]{args[0]};
arguments[1] = new String[]{args[1],args[2]};
//Then retrieve info from object later by casting
System.out.println(java.util.Arrays.toString((String[]) arguments[1]));
}
}
...
Although, please consider using a collection...

While I waited for the answer, I found a way to solve the problem.
The relevant information here is that we do not need to set the second array dimension in its instantiation.
The code is below:
// INPUT string = "2-3,1,4-5"
private static String[][] featuresConversion(String string) {
String[] firstLevel = string.split(","); // 1st lvl separator
String[][] features = new String[firstLevel.length][]; // Sets 1st lvl length only
int i = 0;
for (String element : firstLevel) {
features[i++] = element.split("-");
}
return features;
}
I want to thank you all. All suggested solutions also work fine!

How do I put certain elements(String) in Array into a new array(Integer)?

So I have a text file that looks like this
4
10 orange
20 grape
100 Pencil Cases
4 Card
The first line is the number of objects. The next lines are the price and the name of the object. I have to find the object with the lowest price and return only the name of the object. (So, in this case "Card")
I put the txt into an Arraylist and split it so I could only get the numbers. I am trying to put the numbers into a new integer array to compare them. And this is the code I've tried.
public class Assignment {
public static void main(String[] args) {
try {
BufferedReader rd = new BufferedReader(new FileReader("C:\\Users\\USER\\Documents\\input.txt"));
List<String> lines = new ArrayList<String>();
String line = null;
while ((line = rd.readLine()) != null)
{
lines.add(line);
}
rd.close();
for (int i =0; i<lines.size(); i++) {
String[] items = lines.get(i).split(" ", 2);
for (String s: items) {
System.out.println(s);
}
int[] array2 = new int[items.length];
int k =0;
for (int n= 2; n< items.length; n=n+2) {
array2[k] = Integer.parseInt(items[n]);
for (Integer l: array2) {
System.out.println(l); }
}
}
}
catch (Exception e) {
System.out.println("Error");
}
}
}
I think something is wrong with the array2 part. Can someone give a hint on how I should fix this?? New to stackoverflow and Java so I'm sorry if there is a problem with my question(or my grammar too...)!

I am trying to put the numbers into a new integer array to compare them
Here's how you can do it.
int[] array2 = new int[lines.size() - 1];
int k = 0;
for (int i = 1; i < lines.size(); i++) { //Start at row 1
String[] items = lines.get(i).split(" ", 2);
array2[k++] = Integer.parseInt(items[0]); //The first element is the price
}
System.out.println(Arrays.toString(array2)); //[10, 20, 100, 4]
But, with this, you cannot get the name of the item with the maximum price. So, you need to store both the name and the price together which I'll leave it to you.

How do I split a string into even parts then populate an array with those new strings?

I am working on a program and I will be asking the user to input a string full of characters with no spaces. I will then be splitting this string up into parts of three characters each, and I would like to populate an array with these new strings of three characters. So basically what I am asking is how would I create a method that takes an input string, splits it up into separate parts of three, then populates an array with it.
while (i <= DNAstrand.length()-3) {
DNAstrand.substring(i,i+=3));
}
This code will split the string up into parts of three, but how do I assign those values to an array in a method?
Any help is appreciated thanks!

Loop through and add all the inputs to an array.
String in = "Some input";
//in.length()/3 is automatically floored
String[] out = new String[in.length()/3];
int i=0;
while (i<in.length()-3) {
out[i/3] = in.substring(i, i+=3);
}
This will ignore the end of the String if it's length isn't a multiple of 3. The end can be found with:
String remainder = in.substring(i, in.length());
Finally, if you want the remainder to be part of the array:
String in = "Some input";
//This is the same as ceiling in.length()/3
String[] out = new String[(in.length()-1)/3 + 1];
int i=0;
while (i<in.length()-3) {
out[i/3] = in.substring(i, i+=3);
}
out[out.length-1] = in.substring(i, in.length());

Try this:
private static ArrayList<String> splitText(String text)
{
ArrayList<String> arr = new ArrayList<String>();
String temp = "";
int count = 0;
for(int i = 0; i < text.length(); i++)
{
if(count < 3)
{
temp += String.valueOf(text.charAt(i));
count++;
if(count == 3)
{
arr.add(temp);
temp = "";
count = 0;
}
}
}
if(temp.length() < 3)arr.add(temp);//in case the string is not evenly divided by 3
return arr;
}
You can call this method like this:
ArrayList<Strings> arrList = splitText(and the string you want to split);

Sorting an array of strings [duplicate]

This question already has an answer here:
Remove a common word from each string value in an array
(1 answer)
Closed 6 years ago.
I have an array of Strings that contains: Extra Water, Juice, and Extra Milk, so I am wondering how would I get rid of the extras and use the only second word in the string so that the expected output is Water, Juice, and Milk.

If all you want to do is remove a specific substring then:
String[] array = {"Extra Water", "Juice", "Extra Milk"};
array = Arrays.stream(array).map(s-> s.replaceAll("Extra", "")).toArray();
This uses Java 8 streams but you could do it just as simply with iteration.

Use String.split(' ') to split the string by a space, then check the result to see if the string length == 2. If so, then take the second element of the array, otherwise the first.
for( int i = 0; i < array.length; i++ ) {
String[] parts = array[i].split(' ');
if( parts.length == 2 ) {
array[i] = parts[1];
}
}
EDIT: If you want to remove all duplicate words, you could do the following using two passes over the array:
// Pass 1 -- find all duplicate words
Set<String> wordSet = new HashSet<>();
Set<String> duplicateSet = new HashSet<>();
for (int i = 0; i < array.length; i++) {
String[] parts = array[i].split(" ");
for (String part : parts) {
if (!wordSet.contains(part)) {
// Haven't seen this word before
wordSet.add(part);
} else {
// This word is a duplicate word
if (!duplicateSet.contains(part)) {
duplicateSet.add(part);
}
}
}
}
// Pass 2 -- remove all words that are in the duplicate set
for (int i = 0; i < array.length; i++) {
String[] parts = array[i].split(" ");
String dedupedString = "";
for (String part : parts) {
if (!duplicateSet.contains(part)) {
dedupedString += part + " ";
}
}
array[i] = dedupedString;
}

Simply you need to iterate over each element of the array and replace the "Extra" in each element of the array and then trim the white spaces.
String[] array = {"Extra Water", "Juice", "Extra Milk"};
for (int i = 0; i < array.length; i++) {
array[i] = array[i].replace("Extra", "").trim();
}
for (String each : array) {
System.out.println(each);
}

Separating the int values based on the occurrance of sequence of the values in java?

i have an integer values as:
1299129912
i want to store it as
12
12
12
in the int v1,v2,v3;
i.e.,when ever 9909 occurs we need to separate the values individually. Is it possible in java. If so please anyone help me.
here is the code I'm trying
int l = 1299129912;
Pattern p = Pattern.compile("99");
Matcher m1 = p.matcher(l);
if (m1.matches()) {
System.out.println("\n");
}
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The method matcher(CharSequence) in the type Pattern is not applicable for the arguments (int)

I suppose you already have the value as a String since 1234990912349909 is more that Integer.MAX_VALUE. Then you can split the string into String[] and do whatever you want with the separate values. E.g. call parseInt on each element.
String[] values = myIntString.split("9909");
for (String value: values) {
int v = Integer.parseInt(value);
}

Yes, it is very possible in java. Just convert the integer to a string and replace the 9909 with a space.
Example:
String s="1234990912349909";
s=s.replaceAll("9909","");
int a=Integer.parseInt(s);
System.out.println(a);
//output would be 12341234

If you know you are always going to have 3 integers named v1, v2, and v3 the following would work:
String[] numbers = l.toString().split("99");
int v1 = Integer.parseInt(numbers[0]);
int v2 = Integer.parseInt(numbers[0]);
int v3 = Integer.parseInt(numbers[0]);
However if you don't know in advance then it might be better to do it like this:
String[] numbers = l.toString().split("99");
int[] v = new int[numbers.length];
for (int i = 0; i < numbers.length; i++)
v[i] = Integer.parseInt(numbers[i]);

I found out this is the easiest way to show you how you can resolve your issue:
I included clear comments on every important step. Please check this:
int num = 1239012390;
// Convert int into a string
String str = String.valueOf(num);
// What separates the values
String toBremoved = "90";
String str1 = "";
// Declare a String array to store the final results
String[] finalStrings = new String[2];
// i will be used as an index
int i = 0;
do {
// Finds and separates the first value into another string
finalStrings[i] = str.substring(0, str.indexOf(toBremoved));
// removes the first number from the original string
str = str.replaceFirst(finalStrings[i], "");
// Remove the next separating value
str = str.replaceFirst(str.substring(str.indexOf(toBremoved), str.indexOf(toBremoved) + toBremoved.length()), "");
// increments the index
i++;
} while (str.indexOf(toBremoved) > 0); // keeps going for a new iteration if there is still a separating string on the original string
// Printing the array of strings - just for testing
System.out.println("String Array:");
for (String finalString : finalStrings) {
System.out.println(finalString);
}
// If you want to convert the values into ints you can do a standard for loop like this
// Lets store the results into an int array
int [] intResults = new int [finalStrings.length];
for (int j = 0; j < intResults.length; j++) {
intResults[j] = Integer.valueOf(finalStrings[j]);
}
// empty line to separate results
System.out.println();
// Printing the array of ints
System.out.println("int Array:");
for (int intResult : intResults) {
System.out.println(intResult);
}
Or in a simplified and more accurate way:
(you can use the example above if you need to understand how it can be done the long way)
int num = 1239012390;
String [] numbers = String.valueOf(num).split("90");
int num1 = Integer.parseInt(numbers[0]);
int num2 = Integer.parseInt(numbers[1]);
System.out.println("1st -> " + num1);
System.out.println("2nd -> " + num2);