simple java(二)---output and input

在JAVA上應用對話框(dialogue box)
例一.

import javax.swing.JOptionPane;

public class Hello3 {

public static void main( String args[] )

{
JOptionPane.showMessageDialog(null,

"Welcome\nto\nJava\nProgramming!" );

System.exit( 0 ) ; }

執行結果
welcome
to
java
Programming!

等本人解釋以上的結構和內容

一.當你想應用某些功能,你必需import 一D野..好似你想應用 對話框,你就要import javax.swing.JOptionPane

二. showMessageDialog <<<< 把你的內容SHOW出黎.

三.System.exit( 0 ) <<<> Calls static method exit of class System

例二.

import javax.swing.JOptionPane;

public class Addition {

public static void main( String args[] ) {

String firstNumber;

String secondNumber;

int number1;

int number2;

int 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 ); } }

執行結果
Enter first integer
45
Enter second integer
72
The sum is
117

等本人解釋以上的結構和內容

一.JOptionPane.PLAIN_MESSAGE <<<< 表示 NO ICON,displays a dialog that contains a message.

二. showInputDialog <<< 輸入框

如: Convert to Integer: Integer.parseInt(value)

Convert to Double: Double.parseDouble(value)

三..int ,string 呢D係要黎宣告你想用咩 data type/

.......................................................................

例三.

import java util. *;

public class Input3 {

public static void main( String args[] ) {

int number1;

int number2;

int sum;

Scanner sc = new Scanner(System.in);

System.out.print("Enter first integer: ");

number1 = sc.nextInt();

System.out.print("Enter second integer: ");

number2 = sc.nextInt();

sum = number1 + number2;

System.out.println("The sum is "+sum); }}

呢個程式係應用 Scanner,use import java.util.*;