前端部分面試題目整理

1.javascript

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var name='武老闆';
    function func(){
        var name='李傑';
        function inner() {
            alert(name);            
        }
        return inner;
    }
    var ret=func();
    ret()
</script>
</body>
</html>

測試結果:html

2.java

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script type="text/javascript">

    function main() {
        if (1 == 1) {
            var name = '武老闆';
        }
        console.log(name);
    }
    main()
</script>
</body>
</html>

測試結果:
　　沒有打印出任何東西函數

3.測試

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    xo='alex';
    function func() {
        var xo = '武老闆';
        function inner() {
            var xo='老男孩';
            console.log(xo);
        }
        inner();
    }
    func();
</script>
</body>
</html>

測試結果:this

　　沒有打印出任何東西spa

4.code

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    function Foo() {
        console.log(xo);
        var xo='武老闆';
    }
    Foo();
</script>
</body>
</html>

結果:htm

沒有打印出任何東西blog

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var name='alex';
    function Foo() {
        this.name='武老闆';
        this.func=function () {
            alert(this.name);
        }
    }
    var obj=new Foo();
    obj.func()
</script>
</body>
</html>

結果:

彈框

6.重點題目(詳細瞭解that和this的區別)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var name='alex';
    function Foo() {
        this.name='武老闆';
        this.func=function () {
　　　　　//注意這裏是自執行函數,這裏的this指的是上邊的function結果天然是alex了　
            (function() {
                alert(this.name);
            })()
        }
    }

    var obj=new Foo();
    obj.func()
</script>
</body>
</html>

結果: