simple java(四)--if-else(1)

條件判斷式

if /else

例一.

import javax.swing.*; //用對話框

public class IsEven2 {

public static void main( String args[] ){

String inStr; //要入既String

int num; //宣告 要入既數

String answer;

inStr = JOptionPane.showInputDialog("Enter a number." );

num = Integer.parseInt( inStr );

if (num % 2 == 0) //如果你輸入的數字..除2.餘數係0

answer = "even"; //答案雙數.

else //不是的話

answer = "odd"; //答案單數.

JOptionPane.showMessageDialog( null,num + " is " + answer + ".", "Results",JOptionPane.PLAIN MESSAGE );

System.exit( 0 ); }}

執行結果:

Enter a number

50

50 is even

else-if

例二.

import javax.swing.*;

public class Bonus {

public static void main( String args[] ) {

String inStr;

int salesAmt, bonus;

inStr = JOptionPane.showInputDialog( "Enter a number." );

salesAmt = Integer.parseInt( inStr );

if ( salesAmt > 1000 ) {

bonus = 5000;}

else if( salesAmt > 800 )

{bonus = 3000;}

else if (salesAmt > 600)

{bonus = 2000;}

else if (salesAmt > 400)

{bonus = 1000;}

else if (salesAmt > 200)

{bonus = 500;}

else

{bonus = 0;}

JOptionPane.showMessageDialog( null,"The bonus is"+ bonus +" .");

System.exit( 0 ); }}

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