java--程序流控制

if else

package com.ruqi.keybox;
public class InputWord {
    public static void main(String[] args) {
        int sorce = 99;
        // if(表达式){程序}，大括号可不填
        if (sorce == 99) {
            System.out.println("您的分数为" + sorce);
        }
 
        //if(表达式){程序}else{程序}
        if (sorce > 99) {
            System.out.println("您的分数大于99");
        }
        else {
            System.out.println("您的分数不大于99");
        }
        // if(表达式){程序}else if表达式){程序}else
        if (sorce > 99) {
            System.out.println("您的分数大于99");
        }
        else if(sorce == 99){
            System.out.println("您的分数等于" + sorce);
        }
        else{
            System.out.println("您的分数不满足要求");
        }
    }
}

switch

// case不支持double,float,long类型
public class SwitchDemo {
    public static void main(String[] args) {
        String weekday = "周一";
        switch (weekday){
            case "周一" :
                System.out.println("今天是周一");
                break;
            case "周二" :
                System.out.println("今天是周二");
                break;
            case "周三" :
                System.out.println("今天是周三");
                break;
            default:
                System.out.println("今天是周四");
        }
    }
}

for 循环

 
public class ForDemo2 {
    public static void main(String[] args) {
        //输出三次hello
        for (int i = 0; i < 3 ; i+=1){
            System.out.println("hello");
        }
    }
}

while循环

public class WhileDemo {
    public static void main(String[] args) {
        int i = 1;
        while (i < 3){
            System.out.println("hello");
            i++;
        }
    }
}

 do while

public class WhileDemo {
    public static void main(String[] args) {
        int i = 0;
        do{
            System.out.println("hello");
            i++;
        }while (i < 3);
    }
}