方法一：
package com.liaojianya.chapter1;
import java.util.Scanner;
public class SwitchDemo1
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.println("Enter number a : ");
double a = input.nextDouble();
System.out.println("Enter number b : ");
double b = input.nextDouble();
Action ac = new Action(a, b);
ac.command(Action.ADD);
ac.command(Action.SUBTRACT);
ac.command(Action.MULTIPLY);
ac.command(Action.DIVIDE);
ac.command(Action.MOD);
input.close();
}
}
class Action
{
double a;
double b;
public Action(double a, double b)
{
this.a = a;
this.b = b;
}
public static final int ADD = 1;
public static final int SUBTRACT = 2;
public static final int MULTIPLY = 3;
public static final int DIVIDE = 4;
public static final int MOD = 5;
public void command(int c)
{
switch (c)
{
case 1:
System.out.println(a + " + " + b + " = " + (a + b));
break;
case 2:
System.out.println(a + " - " + b + " = " + (a - b));
break;
case 3:
System.out.println(a + " * " + b + " = " + (a * b));
break;
case 4:
System.out.println(a + " / " + b + " = " + (a / b));
break;
case 5:
System.out.println(a + " % " + b + " = " + (a % b));
break;
default:
System.out.println("unknown operation!");
break;
}
}
}
方法二：
package com.liaojianya.chapter1;
import java.util.Scanner;
/**
* This program demonstrates the use of switch.
* @author LIAO JIANYA
*
*/
public class SwitchDemo
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.println("Enter number a : ");
double a = input.nextDouble();
System.out.println("Enter number b : ");
double b = input.nextDouble();
System.out.println("Enter operater :1代表+，2代表-，3代表*，4代表/，5代表% ");
int c = input.nextInt();
switch(c)
{
case 1:
System.out.println(a + " + " + b + " = " + (a + b));
break;
case 2:
System.out.println(a + " - " + b + " = " + (a - b));
break;
case 3:
System.out.println(a + " * " + b + " = " + (a * b));
break;
case 4:
System.out.println(a + " / " + b + " = " + (a / b));
break;
case 5:
System.out.println(a + " % " + b + " = " + (a % b));
break;
default:
System.out.println("unknown operation!");
break;
}
}
}
运行结果：
Enter number a :
12.3
Enter number b :
32.1
12.3 + 32.1 = 44.400000000000006
12.3 - 32.1 = -19.8
12.3 * 32.1 = 394.83000000000004
12.3 / 32.1 = 0.38317757009345793
12.3 % 32.1 = 12.3
