发布于 2016-09-22 06:23:39 | 129 次阅读 | 评论: 0 | 来源: 网友投递
这里有新鲜出炉的Javascript教程，程序狗速度看过来！
JavaScript客户端脚本语言
Javascript 是一种由Netscape的LiveScript发展而来的原型化继承的基于对象的动态类型的区分大小写的客户端脚本语言，主要目的是为了解决服务器端语言，比如Perl，遗留的速度问题，为客户提供更流畅的浏览效果。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>array-remove-repeate</title>
<style>
.tt{ background-color:#006699; height:3px; overflow:hidden;}
</style>
</head>
<body>
<div class="tt"></div>
<div class="result" id="result"></div>
<script>
if(!console)
{
var console={};
console.log=function(str){alert(str);}
}
Array.prototype.unique1 = function () {
var r = new Array();
label:for(var i = 0, n = this.length; i < n; i++) {
for(var x = 0, y = r.length; x < y; x++) {
if(r[x] == this[i]) {
continue label;
}
}
r[r.length] = this[i];
}
return r;
}
Array.prototype.unique2 = function () {
return this.sort().join(",,").replace(/(,|^)([^,]+)(,,\2)+(,|$)/g,"$1$2$4").replace(/,,+/g,",").replace(/,$/,"").split(",");
}
Array.prototype.unique3 = function() {
var temp = {}, len = this.length;
for(var i=0; i < len; i++) {
var tmp = this[i];
if(!temp.hasOwnProperty(tmp)) {
temp[this[i]] = "my god";
}
}
len = 0;
var tempArr=[];
for(var i in temp) {
tempArr[len++] = i;
}
return tempArr;
}
Array.prototype.unique4 = function () {
var temp = new Array();
this.sort();
for(i = 0; i < this.length; i++) {
if( this[i] == this[i+1]) {
continue;
}
temp[temp.length]=this[i];
}
return temp;
}
var test=(function()
{
var arr2=[];
for(var i=0;i<2000;i++)
{
var t=i;
t=parseInt(Math.random()*2000)+1;
arr2[i]=(t.toString());
}
//arr2=["zhoujian","zhou","zhou"];
return function(){
return arr2;
//return [1,2,3,3];
};
})();
window.onload=function(){
//
Watch.start("Cost times1:");
var arr= test();
console.log(arr.length );
arr=arr.unique1();
console.log(arr.length);
Watch.stop();
//
Watch.start("Cost times2:");
arr= test();
console.log(arr.length);
arr=arr.unique2();
console.log(arr.length);
Watch.stop();
//
Watch.start("Cost times3:");
arr= test();
console.log(arr.length );
arr=arr.unique3();//数组很大时，最快
console.log(arr.length );
Watch.stop();
//
Watch.start("Cost times4:");
arr= test();
console.log(arr.length);
arr=arr.unique4();
console.log(arr.length);
Watch.stop();
Watch.report();
}
</script>
</body>
</html>
var Watch = {
result: [],
guid: -1,
totalTime: 0,
start: function(title){
this.result[++this.guid] = [title || this.guid, new Date().getTime()];
},
stop: function(){
var r = this.result[this.guid];
var t = new Date().getTime() - r[1];
this.totalTime += t;
r[1] = t;
if(t>=10000){
alert("This code takes too long to run,you should optimizate them.");
}
},
report: function(parent){
var div = document.createElement("div");
div.style.fontSize = "12px";
var str = [];
str.push("<p><b>The total times:</b><span style='color:#f00'>" + this.totalTime + "</span> ms.</p>");
for (var i = 0, l = this.result.length; i < l; i++) {
if (this.result[i].length > 1) {
str.push("<p>" + "<span style='width:200px;display:inline-block;background-color:#f7f7f7;-moz-border-radius:3px;-webkit-border-radius:3px;border-radius:3px;'>"+"<span style='background-color:#0c0; -moz-border-radius:3px;-webkit-border-radius:3px;border-radius:3px;width=" + (this.totalTime === 0 ? this.totalTime : parseInt(200 * this.result[i][1] / this.totalTime)) + "px; display:inline-block;'>"+this.result[i][1]+"</span>"+"</span> <span style='width:150px; display:inline-block;'>" + this.result[i][0] + "</span>" + "</p>");
}else{
str.push(this.result[i][0]);
}
}
div.innerHTML = str.join("");
parent = parent || document.body;
parent.appendChild(div);
div = null;
this.totalTime = 0;
this.guid = -1;
this.result=[];
},
fns: function(){
var a = arguments;
for (var i = 0, l = a.length; i < l; i++) {
this.start(a[i][0]);
a[i][1]();
this.stop();
}
},
execByTimes: function(fn, times, title){
this.start(title);
while (times--) {
fn();
}
this.stop();
},
print: function(str){
this.result[++this.guid]=[str];
}
}