Javascript最佳实践

let count = 5
let color = "blue"
let values = [1,2,3]
let now = new Date()

let [count, color, values, now] = [5, ‘blue‘, [1,2,3], new Date()]

const name = "Nicholas";
const age = ‘18‘
function sayName(){
    console.log(‘名字是：‘ + name + ‘ 年龄：‘ + age)
}

const myInfo = {
    name: ‘Nicholas‘,
    age: ‘18‘,
    sayName: function () {
        console.log(‘名字是：‘ + this.name + ‘ 年龄：‘ + this.age)
    }
}

const sayName = function sayName(){
    console.log(‘名字是：‘ + name + ‘ 年龄：‘ + age)
}
const myInfo = {
    name: ‘Nicholas‘,
    age: ‘18‘,
    sayName
}

function sortArray(values){
    if (values != null){    //避免！
        values.sort(comparator);
    }
}

function sortArray(values){
    if (values instanceof Array){    //推荐    当然，判断方式还有如：Object.prototype.toString.call(values).slice(8, -1) === ‘Array‘
        values.sort(comparator);
    }
}

const invalid_value_msg = ‘Invalid value!‘
const incalid_value_url = ‘/errors/invalid.php‘
function validate(value){
    if (!value){
        alert(invalid_value_msg)
        location.href = incalid_value_url
    }
}

const Constants = {
    INVALID_VALUE_MSG: "Invalid value!",
    INVALID_VALUE_URL: "/errors/invalid.php"
}
function validate(value){
    if (!value){
        alert(Constants.INVALID_VALUE_MSG)
        location.href = Constants.INVALID_VALUE_URL
    }
}

const query = window.location.href.substring(window.location.href.indexOf("?"))  //此版本查找了6次

const url = window.location.href
const query = url.substring(url.indexOf("?")) //此版本只查找了4次