页面彩蛋

彩蛋.js

function egg(arr, callback) {
    this.sequence = arr.join(',')
    this.length = arr.length
    this.pressed = []
    this.callback = callback
    this.init()
}

egg.prototype = {
    constructor: egg,
    init: function () {
        document.addEventListener('keyup', this.handleKey.bind(this), false)
    },
    handleKey: function (e) {
        this.pressed.push(e.keyCode)
        console.log(this.pressed)
        this.check()
    },
    check: function () {
        if (this.pressed.join(',') == this.sequence) {
            this.callback()
            this.pressed = []
        } else if (this.pressed.length == this.length) {
            this.pressed.shift()
        }
    },
}

new egg([38, 40, 38, 40], function () {
    alert('go!')
})