Java String substring()

class Main {
  public static void main(String[] args) {
    String str1 = "java is fun";

    // extract substring from index 0 to 3
    System.out.println(str1.substring(0, 4));

  }
}

// Output: java

Syntax of substring()

The syntax of the substring() method is:

string.substring(int startIndex, int endIndex)

substring() Argument

The substring() method can take a maximum of two arguments.

• startIndex - the beginning index
• endIndex (optional) - the ending index

substring() Return Value

The substring() method returns a substring from the given string.

• The substring begins with the character at the startIndex and extends to the character at index endIndex - 1.
• If the endIndex is not passed, the substring begins with the character at the specified index and extends to the end of the string.

Example 1: Java substring() With Only Start Index

class Main {
  public static void main(String[] args) {
    String str1 = "program";

    //  1st character to the last character
    System.out.println(str1.substring(0));  // program


    // 4th character to the last character
    System.out.println(str1.substring(3));  // gram
  }
}

Example 2: Java substring() With Start and End Index

class Main {
  public static void main(String[] args) {
    String str1 = "program";

    // 1st to the 7th  character
    System.out.println(str1.substring(0, 7));  // program

    // 1st to the 5th  character
    System.out.println(str1.substring(0, 5));  // progr


    // 4th to the 5th character
    System.out.println(str1.substring(3, 5));  // gr
  }
}

If you need to find the index of the first occurrence of the specified substring from the given string, use the Java String indexOf() method.