循坏语句

break可以在switch和循坏语句中使用

continue只能在循坏结构中使用

1.if ……else

int a=14;
    int b=5;
    if(a>b) {
        System.out.println("a>b");
    }else if(a<b) {
        System.out.println("a<b");
    }else {
        System.out.println("a=b");
    }

2.switch

char d='B';
    switch(d) {
    case 'A':
        System.out.println("80~100");
        break;
    case 'B':
        System.out.println("70~80");
        break;
    case 'C':
        System.out.println("60~70");
        break;
    default:
        System.out.println("60以下");

3.for循坏

    String s="";
    for(int a=1;a<10;a++) {
        for(int b=1;b<=a;b++) {
        s+=a+"*"+b+"="+(a*b)+"\t";
        }
        s+="\n";
    }
    System.out.println(s);
    

4.do……while

    int a=1;
    String s="";
    do {
        int b=a;
        do {
        s+=a+"*"+b+"="+(a*b)+"\t";
        b++;
        }while(b<10);
        s+="\n";
        
        a++;
        
    }while(a<10);
    System.out.println(s);

5.while

int a=1;
    String s="";
    while(a<10) {
        int b=a;
        while(b<10
                ) {
            s+=a+"*"+b+"="+(a*b)+"\t";
            b++;
        }
        a++;
        s+="\n";
    }
System.out.println(s);
}