import javax.swing.JOptionPane;

public class Addition { public static void main( String args[] ) {

String firstNumber,secondNumber;

int number1, number2, sum;

firstNumber =JOptionPane.showInputDialog( "Enter first integer" );

secondNumber = JOptionPane.showInputDialog( "Enter second integer" );

number1 = Integer.parseInt( firstNumber );

number2 = Integer.parseInt( secondNumber );

sum = number1 + number2;

JOptionPane.showMessageDialog( null, "The sum is " + sum, "Results", JOptionPane.PLAIN_MESSAGE );

System.exit( 0 );

}

}

兩數求和java（字符串強轉int型）