Java valueOf() Method: Usage and Examples

Description:

The valueOf method returns the relevant Number Object holding the value of the argument passed. The argument can be a primitive data type, String, etc.

This method is a static method. The method can take two arguments, where one is a String and the other is a radix.

Syntax:

All the variants of this method are given below:

static Integer valueOf(int i)
static Integer valueOf(String s)
static Integer valueOf(String s, int radix)

The static valueOf method can be used to convert an array of characters into a string. There are several overloaded versions of the valueOf method that can be used to convert a charac- ter and numeric values to strings with different parameter types, char , double , long , int , and float

Parameters:

Here is the detail of parameters:

• i -- An int for which Integer representation would be returned.

• s -- A String for which Integer representation would be returned.

• radix -- This would be used to decide the value of returned Integer based on passed String.

Return Value:

• valueOf(int i): This returns an Integer object holding the value of the specified primitive.

• valueOf(String s): This returns an Integer object holding the value of the specified string representation.

• valueOf(String s, int radix): This returns an Integer object holding the integer value of the specified string representation, parsed with the value of radix.

public class Test{ 

   public static void main(String args[]){
      
      Integer x =Integer.valueOf(9);
      Double c = Double.valueOf(5);
      Float a = Float.valueOf("80");               

      Integer b = Integer.valueOf("444",16);

      System.out.println(x); 
      System.out.println(c);
      System.out.println(a);
      System.out.println(b);
   }
}

This produces the following result:

9
5.0
80.0
1092

Example

// Java program to demonstrate valueOf() method
public class ValueOfMethod
{
    public static void main(String[] args)
    {
        // demonstrating valueOf(int i) method
        System.out.println("Demonstrating valueOf(int i) method");
        Integer i =Integer.valueOf(50);
        Double d = Double.valueOf(9.36);
        System.out.println(i);
        System.out.println(d);

        // demonstrating valueOf(String s) method
        System.out.println("Demonstrating valueOf(String s) method");
        Integer n = Integer.valueOf("333");
        Integer m = Integer.valueOf("-255");
        System.out.println(n);
        System.out.println(m);

        // demonstrating valueOf(String s,int radix) method
        System.out.println("Demonstrating (String s,int radix) method");
        Integer y = Integer.valueOf("333",8);
        Integer x = Integer.valueOf("-255",16);
        Long l = Long.valueOf("51688245",16);
        System.out.println(y);
        System.out.println(x);
        System.out.println(l);

        // run-time NumberFormatException will occur in below cases
        Integer a = Integer.valueOf("Hello");
        Integer b = Integer.valueOf("Hello",16);
    }
}

This will produce the following result ?

Output

Demonstrating valueOf(int i) method
50
9.36
Demonstrating valueOf(String s) method
333
-255
Demonstrating (String s,int radix) method
219
-597
1365803589
Exception in thread "main" java.lang.NumberFormatException: For input string: "Hello"
        at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
        at java.lang.Integer.parseInt(Integer.java:580)
        at java.lang.Integer.valueOf(Integer.java:766)
        at ValueOfMethod.main(ValueOfMethod.java:30)
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