//伪代码
if (关系表达式)
    代码块

//伪代码
if (关系表达式)
    代码块1
else
    代码块2

//伪代码
if (关系表达式1)
    代码块1
else if(关系表达式2)
    代码块2
else
    代码块3

if (score >= 90)
    System.out.println("A");
else if (score >= 80)
    System.out.println("B");
else if (score >= 60)
    System.out.println("C");
else
    System.out.println("Fail");

switch (表达式) {
    case val0:
        break;
    case val1:
        break;
    ...
    case valN:
        break;
    default:
        break;
}

switch (score/10) {
    case 7:
    case 8:
    System.out.println("B");
    break;
    case 9:
    System.out.println("A");
    break;
    case 6:
    System.out.println("C");
    break;
    default:
    System.out.println("D");
        break;
}

switch (day) {
    case 1:
    case 2:
    case 3:
    case 4:
    case 5:
        System.out.println("Workday");
        break;
    case 6:
    case 7:
        System.out.println("Restday");
        break;
    default:
        System.out.println("Wrongday");
        break;
}

for( 初始化循环语句; 循环判断语句; 循环迭代语句){
    循环体语句;
}

for (int i = 0; i <= 100; i++) {
    if (i % 2 == 0) {
        System.out.println(i);
    }
}

while( 循环条件语句){
    循环体语句;
}

do{
    循环体语句;
}while( 循环条件语句);