The Java core API possesses a method equivalent to the C atoi() function in Java. The java.lang.Integer class contains a method called parseInt()which will convert a String into an int. The Float, Double, and Longclasses also contain analogous methods to convert strings into numbers.They also contain toString() methods to perform the conversion of numbersinto strings. The following program will take two arguments, add them,and print the result:

 public final class ParseIntExample {  public static final void main(String[] args) {    int num1, num2, sum;    if(args.length != 2) {      System.err.println("Usage: ParseIntExample  ");      return;    }    try {      num1 = Integer.parseInt(args[0]);      num2 = Integer.parseInt(args[1]);    } catch(NumberFormatException e) {      System.err.println("You must provide two   
integer arguments.");      return;    }    sum = num1 + num2;    System.out.println(num1 + " + " + num2 + " = " + sum);  }}