setTimeout 定时器

1.快速多次点击只触发最后一次

var hander = 0;

    function btnClick() {

        if (hander != 0) {

            clearTimeout(hander);

            hander = 0;

        }

        hander = setTimeout(function () {

            Run();

        }, 300);

    }

    function Run() {

        console.log('Run');

    }

<input type="button" onclick="btnClick()" value="快速点击只触发最后一次" />