int i , a = 10 , b = 3; //定义变量
i = a mod b; //相当于 i = a % b ;计算结果是 i 的值为1

// An addition program

import javax.swing.JOptionPane;  // import class JOptionPane

public class Addition {
    public static void main( String args[] )
    {
        String firstNumber,   // first string entered by user
                secondNumber;  // second string entered by user
        int number1,          // first number to add
                number2,          // second number to add
                sum;              // sum of number1 and number2

        // read in first number from user as a string
        firstNumber =
                JOptionPane.showInputDialog( "Enter first integer" );

        // read in second number from user as a string
        secondNumber =
                JOptionPane.showInputDialog( "Enter second integer" );

        // convert numbers from type String to type int
        number1 = Integer.parseInt( firstNumber );
        number2 = Integer.parseInt( secondNumber );

        // add the numbers
        sum = number1 + number2;

        // display the results
        JOptionPane.showMessageDialog(
                null, "The sum is " + sum, "Results",
                JOptionPane.PLAIN_MESSAGE );

        System.exit( 0 );   // terminate the program
    }
}