In this section, we will learn what the String substring() method is and how to use it in Java.

What is Java String substring() Method?

The `substring()` method is used when we want to get a portion or substring of a string value.

For example, we have a message like:

“Nobody ever drowned in his own sweat”

And we want to get the “Nobody ever drowned” part of this message and return it as a new string object. This is where we can use the `substring()` method.

Java substring() Method Syntax:

public String substring(int startIndex)

public String substring(int startIndex, int endIndex)

substring() Method Parameters:

• `startIndex`: this is the starting index number from which we want to take a substring at that point.

Note: this index is inclusive.

• `endIndex`: this is the end index where the end of the substring will be.

Notes:

• This end index is exclusive.
• Also, if we don’t set the second argument (endIndex), by default the last index of the target string will be considered as the end of the substring as well.

substring() Method Return Value:

The return value of this method is of type string, which is the substring that we wanted to take out from the target string value.

substring() Method Exceptions:

We will get an exception of type `StringIndexOutOfBoundsException` if we set an index number that is out of the range of the target string value.

Example: using String substring() method

public class Simple {

    public static void main(String[] args)  {
        String w = "Life is amazing!";
        String sub1 = w.substring(8);
        String sub2= w.substring(0,4);
        System.out.println(sub1);
        System.out.println(sub2);
    }
}

Output:

amazing

Life

 

Example: Java String substring() method

public class Simple {

    public static void main(String[] args)  {
        String w = "Nobody ever drowned in his own sweat";
        String sub= w.substring(0,19);
        System.out.println(sub);
    }
}

Output:

Nobody ever drowned