Method split()

The split(String delimiter) method splits a string into an array of substrings based on the specified delimiter (a character or sequence of characters). It returns an array where each element is a substring from the original string, separated by the delimiter.

How to split String into String[]

Let's say we have a task to split a sentence into an array of words. In this case, we can either append until we encounter a space character (" "), or we can use the split() method.

The split() method is a String method that takes a regex as a parameter. What is regex? Regex stands for regular expression, which is essentially a character or set of characters that we use to split our string. We can input a space character " " in the regex, and then our sentence will be divided into words. Let's take a look at an example:

Main


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package com.example;

//do not modify the code below this comment

public class Main {
    public static void main(String[] args) {
        String string = "This is the sentence that we want to split";
        // split the string into an array based on spaces
        String[] array = string.split(" ");  
        printArray(array);
    }

    // method to print each element of the array
    static void printArray(String[] array) {
        for (String element: array) {
            System.out.println(element + " ");
        }
    }
}

Here we have split the string into an array of words. We used " " to indicate to the program that it should split the sentence at each occurrence of " ".

How to split a String by a specific character

We can also split our string using any other character. For example, let's split the link at the occurrence of the character "/".

Main


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package com.example;

// do not modify the code below this comment

public class Main {
    public static void main(String[] args) {
        String link = "codefinity.com/profile/my-home";
        // split the string into an array based on "/"
        String[] array = link.split("/");  
        printArray(array);  // print the array elements
    }

    // method to print each element of the array
    static void printArray(String[] array) {
        for (String element: array) {  
            System.out.println(element + " ");  
        }
    }
}

We have split the URL into separate parts at each occurrence of the "/" character, and now we can see each element of the URL. In other words, when we split the string at the "/" character, we obtained an array of strings.

You may also notice that the method removes the specified character from the resulting array when splitting.

How to split a String into characters with String type

To split a string into an array at each occurrence of a single character, we can simply use empty quotation marks "" as the parameter. Let's take a look at an example:

Main


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package com.example;

// do not modify the code below this comment

public class Main {
    public static void main(String[] args) {
        String string = "c<>definity";
        // split the string into an array of individual characters
        String[] array = string.split("");  
        printArray(array);
    }

    // method to print each element of the array
    static void printArray(String[] array) {
        for (String element: array) {  
            System.out.print(element + " ");  
        }
        // print a new line after the array elements
        System.out.println();  
    }
}

We have split the string into individual letters. You might think that there is a specific method for this, like toCharArray(), but the difference is that when using the split() method, we obtain an array of elements of type String, whereas with toCharArray(), we directly obtain an array of elements of type char.

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Seção 3. Capítulo 2