数组,对象的解构.常用的流程控制方法!

1.数组与对象的解构

解构要求等号二边类型一致

数组解构

<script>
    const cars = ['volvo', ['bmw-x1', 'bmw-x2', 'bmw-x3'], 'benz', ];
    [car1, [car2, car3, car4], car5] = cars;
    console.log(car1, car2, car3, car4, car5);
</script>

对象解构

<script>
    const school = {
        name: '城关小学',
        class: '二班',
        number: 56,
    };
    ({name,classes,number,} = {name: '城关小学',classes: '二班',number: 56,});
    console.log(name, classes, number)
</script>

2.流程控制方法

单分支

<script>
    let score = 61;
    if (score >= 60) console.log('合格');
</script>

双分支

<script>
    let score = 59;
    if (score >= 60) console.log('合格');
    else console.log('明年再来.加油!')
</script>

多分支

<script>
    let score = 104;
    if (score >= 60 && score < 80) console.log('合格');
    else if (score >= 80 && score <= 100) console.log('优良');
    else if (score > 100 || score < 0) console.log('非法分数');
    else console.log('明年再来.加油!')
</script>

switch语句用法

<script>
    let exam = 'error';
    switch (exam) {
        case 'fail':console.log('考试失败');break;
        case 'success':console.log('考试过关');break;
        case 'error':console.log('未参加考试');break;
        default:console.log('请输入正确的名字');
    }
</script>