The valueOf() method of the String class in Java helps to convert various data types like integers, floats, booleans, and objects into their string representations. It makes it simple to work with string manipulation, logging, and displaying data efficiently.

Example:

To convert a number into text for easy display or use in-text operations, we can use the valueOf() method.

// Java program to demonstrate
// working of valueOf() method
public class ValueOf {
  
    public static void main(String[] args) {
      
        int n = 21;     // Declare an integer
        String s = String.valueOf(n);       // Convert integer to string
        System.out.println("String representation: " + s); 
    }
}

// Java program to demonstrate

// working of valueOf() method

public class ValueOf {

    public static void main(String[] args) {

        int n = 21;     // Declare an integer

        String s = String.valueOf(n);       // Convert integer to string

        System.out.println("String representation: " + s); 

    }

}

String representation: 21

Explanation: The number 21 is converted to the string "21" for easier use in text-related tasks.

Syntax of valueOf() Method

The syntax of valueOf() method for different kind of inputs are:

public static String valueOf(int i)

public static String valueOf(long l)

public static String valueOf(float f)

public static String valueOf(double d)

public static String valueOf(boolean b)

public static String valueOf(char c)

public static String valueOf(char[] data)

public static String valueOf(char[] data, int offset, int count)

public static String valueOf(Object obj)

Return Type: It returns a String that represents the input data. If the input is null, it returns the text "null".

Other Examples of String valueOf() Method

1. Convert Boolean to String Using valueOf()

Example:

public class ValueOf {
  
    public static void main(String[] args) {
      
        boolean b = true;      // Boolean variable
        String s = String.valueOf(b);      // Convert boolean to string
        System.out.println("" + s); 
    }
}

public class ValueOf {

    public static void main(String[] args) {

        boolean b = true;      // Boolean variable

        String s = String.valueOf(b);      // Convert boolean to string

        System.out.println("" + s); 

    }

}

true

Explanation: In the above example, the boolean true becomes the string "true" for display or text use.

2. Convert Object to String Using valueOf()

Example:

public class ValueOf {
  
    public static void main(String[] args) {
      
        Object o = null;      // Null object
        String s = String.valueOf(o);      // Convert object to string
        System.out.println("" + s); 
    }
}

public class ValueOf {

    public static void main(String[] args) {

        Object o = null;      // Null object

        String s = String.valueOf(o);      // Convert object to string

        System.out.println("" + s); 

    }

}

null

Explanation: In the above example, the method converts the null object into the text "null" without errors.

3. Convert Part of a Char Array to String Using valueOf()

Example:

public class ValueOf {
  
    public static void main(String[] args) {
      
        // Character array
        char[] ch = { 'H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd' };  
        String s = String.valueOf(ch, 0, 5);      // Convert first 5 characters to string
        System.out.println("" + s); 
    }
}

public class ValueOf {

    public static void main(String[] args) {

        // Character array

        char[] ch = { 'H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd' };  

        String s = String.valueOf(ch, 0, 5);      // Convert first 5 characters to string

        System.out.println("" + s); 

    }

}

Hello

Explanation: In the above example, the first five characters ('H', 'e', 'l', 'l', 'o') are converted into the string "Hello".