SOURCE

var arr = [1, 2, 3, 4, 5];

(function () {
    for (var i = 0; i < arr.length; i++) {
        console.log(i)
    }
})()

var name = 'window'

var p = {
    name: 'Perter',
    getName: function () {
        return function () {
            return this.name
        }
    }
}

var getName = p.getName()

// 立即执行
var _name = getName.call(p)

console.log(getName)
console.log(_name)