优秀的 JavaScript 代码片段集合

callee.js

//JavaScript callee 用法示例

function factorial(num) {
    if (num <= 1) {
		return 1;
	} else {
		return num * arguments.callee(num - 1);
	}
}
 
console.log(factorial(10)); //3628800

get-city.js

// 获取城市

function getCity(fn, tryTimes) {

    var city = $.cookie("city");
	if (city)
		return city;

	var service = "http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js";
	$.getScript(service, function() {
		var data = remote_ip_info;
		if (!data) {
			tryTimes = tryTimes || 0;
			if (tryTimes < 3)
				return setTimeout(function() {
					getCity(fn, ++tryTimes);
				}, 500);
			else {
				return fn();
			}
		}
		city = data.city ? data.city : (data.province ? data.province : data.country);
		if (city) {
			var expiresTime = new Date();
			expiresTime.setMinutes(expiresTime.getMinutes() + 30);
			$.cookie("city", city, {
				expires: expiresTime,
				raw: true
			});
		}
		fn(city);
	});
}

inherit.js

// JavaScript 继成实现常用方式

function ClassA(name){
    this.name=name;
}
ClassA.prototype.sayName=function(){
	alert(this.name);
}
 
function ClassB(name,age){
	ClassA.call(this,name);
	this.age=age;
}
ClassB.prototype=new ClassA();
ClassB.prototype.sayAge=function(){
	alert(this.age);
}

to-rgb.js

function toRGB(hex) {
        var result = /^#([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
	if (result) {
		return "rgb(" + parseInt(result[1], 16) + "," + parseInt(result[2], 16) + "," + parseInt(result[3], 16) + ")";
	} else {
		var shorthandRegex = /^#([a-f\d])([a-f\d])([a-f\d])$/i;
		return shorthandRegex.test(hex) ? hex : "invalid";
	}
}

// for test
console.log(toRGB("#00FFFF"));
console.log(toRGB("aaa"));
console.log(toRGB("#333"));

unique.js

//JavaScript 数组去重

function unique(arr) {
    var re = [];
	var dic = {};
	for (var i = 0; i < arr.length; i++) {
		var item = arr[i];
		var key = typeof(item) + item;
		if (!dic[key]) {
			re.push(item);
			dic[key] = true;
		}
	}
	return re;
}
unique([1, 2, 3, 4, '2', '3', 2, 4]);