闭包

闭包

   function a(num) {
        return function () {
            console.log(num, 2)
        }
    }
    let s = a(2)
    s()

    var one = (function (i) {
        var num = 10;
        return function () {
            console.log(num++)
        }
    })(2)

闭包的劣势

闭包的好处