zhangsanshi / issue-blog

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记录几个有意思的问题 #33

Open zhangsanshi opened 7 years ago

zhangsanshi commented 7 years ago

1.

<button id="a">xxxx</button>

<script>
    a.onclick = function () {
        console.log(1);
    };
    function b() {
        console.log(2);
        var delay = new Date() - 0 + 10000;
        while (new Date()< delay) {

        }
    }
    b();
</script>

页面加载完成后,接着点击 button a N次,会打印什么?答案

2
1(N次)
  1. 数组去重
    var a = [3,3,4,5,4];

    ES6 答案

    var s = new Set(a);
    var out = [...s];