Java Switch語句

• 語法
• 流程執行圖

語法

switch(expression){    
    case value1:    
       //code to be executed;    
       break;  //optional  
    case value2:    
       //code to be executed;    
       break;  //optional  
    ......    

    default:     
       // code to be executed if all cases are not matched;    
}
 

流程執行圖

如果沒有break

public class SwitchExample2 {
    public static void main(String[] args) {
        int number = 20;
        switch (number) {
        case 10:
            System.out.println("10");
        case 20:
            System.out.println("20");
        case 30:
            System.out.println("30");
        default:
            System.out.println("Not in 10, 20 or 30");
        }
    }
}
 

執行結果：

20
30
Not in 10, 20 or 30