Convert String variable to Integer in java (example)

1. Methods to convert String to Integer in java

• Given an String in java, we would like convert String to integer.
  • Input String strNumber = “9999”
  • The output of program should be iNumber  = 9999
• We can convert String to integer using following methods.
  1. Convert String to integer using Integer.parseInt.
  2. Convert String to integer using Integer.valueOf.
  3. Convert String to integer using Integer constructor.

2. Program – convert String to Integer in java (example)

package org.learn;

public class ConvertStringToInt {
    public static void main(String[] args) {
        String strNumber = "9999";

        //Method 1
        int iNumber = Integer.parseInt(strNumber);
        System.out.printf("1. Convert string to integer using Integer.parseInt: %d",iNumber);
        //Method 2
        iNumber = Integer.valueOf(strNumber);
        System.out.printf("\n2. Convert string to integer using Integer.valueOf: %d",iNumber);
        //Method 3
        iNumber = new Integer(strNumber).intValue();
        System.out.printf("\n3. Convert string to integer using Integer constructor: %d",iNumber);
    }
}

3. Output – Convert String to Integer in java (with example)

1. Convert string to integer using Integer.parseInt: 9999
2. Convert string to integer using Integer.valueOf: 9999
3. Convert string to integer using Integer constructor: 9999