Home Web Front-end JS Tutorial A simple extension for Array_javascript skills

A simple extension for Array_javascript skills

May 16, 2016 pm 07:25 PM

In fact, it is a simplified version of the enumeration object part in prototype 1.4.
I will post the code first and explain it one by one later. It may be helpful to beginners.

I have been learning Python recently and have always been amazed by python. List is flexible,
are also arrays, why can’t javascript be as flexible as python,
(In fact, the following prototype 1.4 has been implemented, but the prototype is too fat, you know, I am obsessed with fat women Not interested)
So we have the following code....

Copy the code The code is as follows:

<script> <br>Array.prototype.map = function(f) {   <br>  var arr=[] <br>  for(var i=0;i<this.length;i ) arr.push(f(this[i])) <BR>  return arr   <BR>} <br><br>Array.prototype.each = function(f) {  <BR>  for(var i=0;i<this.length;i ) f(this[i]) <BR>} <br><br>Array.prototype.find = function(f) {   <BR>  for(var i=0;i<this.length;i )  if (f(this[i])) return this[i] <BR>  return null <BR>} <br><br>Array.prototype.findAll = function(f) {  <BR>  var arr=[] <BR>  for(var i=0;i<this.length;i )  if (f(this[i])) arr.push(this[i]) <BR>  return arr <BR>} <br><br>Array.prototype.getPart = function(f) {    <BR>  for(var i=0;i<this.length;i )  if (f(this[i])) return [this.slice(0,i 1),this.slice(i 1)] <BR>} <br><br><BR>Array.prototype.all = function(f) {  <BR>  for(var i=0;i<this.length;i )  if (!f(this[i])) return false <BR>  return true <BR>} <br><br>Array.prototype.any = function(f) {  <BR>  for(var i=0;i<this.length;i )  if (f(this[i])) return true <BR>  return false <BR>} <br><br>Array.prototype.grep = function(regex,f) {  <BR>  var arr=[] <BR>  for(var i=0;i<this.length;i ){ <BR>     if (this[i].toString().match(regex)) arr.push((f || function(x){return x})(this[i])) <BR>  }   <BR>  return arr <BR>} <br><br>Array.prototype.include = function(v) {  <BR>  for(var i=0;i<this.length;i )  if (this[i]==v) return true <BR>  return false <BR>} <BR>Array.prototype.indexOf = function(v) {  <BR>  for(var i=0;i<this.length;i )  if (this[i]==v) return i <BR>  return -1 <BR>} <br><br>Array.prototype.inject = function(v,f) {  <BR>  var vv=v <BR>  for(var i=0;i<this.length;i )  vv=f(vv,this[i]) <BR>  return vv <BR>} <br><br>Array.prototype.max=function(){ <BR>  var v=this[0]; <BR>  for(var i=0;i<this.length;i )  if (this[i]>v) v=this[i] <br>  return v <br>} <br><br>Array.prototype.min=function(){ <br>  var v=this[0]; <br>  for(var i=0;i<this.length;i )  if (this[i]<v) v=this[i] <BR>  return v <BR>} <br><br>Array.prototype.partition = function(f) {  <BR>  var arr1=[],arr2=[] <BR>  for(var i=0;i<this.length;i )  f(this[i])?arr1.push(this[i]):arr2.push(this[i]) <BR>  return [arr1,arr2] <BR>} <br><br></script>

这里有很多文本和script块,而且script块的数目不定
<script>alert(1)</script>
<script> <br>function fff(){ <br>alert("fff function") <br>} <br>fff()</script>
<script>alert("last alert()")</script>


<script> <br>//对数组中每个元素都调用函数f执行,并把执行的结果按数组原排列顺序返回,返回一个数组 <br>Array.prototype.map = function(f) {   <br>  var arr=[] <br>  for(var i=0;i<this.length;i ) arr.push(f(this[i])) <BR>  return arr   <BR>} <br><br>//对数组中每个元素都调用函数f执行,只执行,不返回结果 <BR>Array.prototype.each = function(f) {   <BR>  for(var i=0;i<this.length;i ) f(this[i]) <BR>} <br><br>//最简单的例子 <BR>var arr=[3,1,5,2,7] <BR>var arr2=arr.map(function(x){return x*x}) <BR>alert(arr2) <br><br>//取整 <BR>var arr3=[3.121,1.555,5.8,2.0,7.9] <BR>var arr4=arr3.map(Math.round) <BR>alert(arr4) <br><br><BR>//返回数组中每个字符串的长度 <BR>var a1=["dasfsdfas","dasffdfs","ds","2","cccccc"] <BR>var a2=a1.map(function(x){return x.length}) <BR>alert(a2) <br><br><BR>//这个例子比较常用,比如用ajax抓了一个页面,怎么执行页面中的所有script块呢?<BR>var f=function(s){return s.replace(/^<script.*?>/,"").replace(/</script>$/,"")}
o.value.match(/(?:)((n|r|.)*?)(?:)/gi).map(f).each( eval)

//More complex examples
// http://community.csdn.net/Expert/topic/4796/4796192.xml?temp=.2977564


<script> <br>//Get the first element that makes function f true, if not found return null <br>Array.prototype.find = function(f) { <br> for(var i=0;i<this.length;i ) if (f(this[i])) return this[i] <br> return null <br>} <br><br>/ /Get all elements that make function f true, if not found return an empty array <br>Array.prototype.findAll = function(f) { <br> var arr=[] <br> for(var i=0; i<this.length;i ) if (f(this[i])) arr.push(this[i]) <br> return arr <br>} <br><br>//Find an even number in the array <br>var arr=[3,1,5,2,7,8,1,0,10] <br>var v=arr.find(function(x){return x%2==0}) <br>alert(v) <br><br>//Find all even numbers<br>var arr2=arr.findAll(function(x){return x%2==0}) <br>alert(arr2) <br><br></script>

<script> <br>//Returns an array containing two elements. Both elements are an array. arr1 is an array composed of all elements that can make f true. arr2 is the remaining elements <br>Array.prototype.partition = function(f) { <br> var arr1=[], arr2=[] <br> for(var i=0;i<this.length;i ) f(this[i])?arr1.push(this[i]):arr2.push(this[i]) <br> return [arr1,arr2] <br>} <br><br>//Return true only if all elements in the array can make f true <br>Array.prototype.all = function(f) { <br> for(var i=0;i<this.length;i ) if (!f(this[i])) return false <br> return true <br>} <br><br>//As long as any one exists Return true if the element can make f true <br>Array.prototype.any = function(f) { <br> for(var i=0;i<this.length;i ) if (f(this[i]) ) return true <br> return false <br>} <br><br>//Find even and odd numbers<br>var arr=[3,1,5,2,7,8,1,0,10] <br>var a=arr.partition(function(x){return x%2==0}) <br>alert(a[0]) //Return all even numbers<br>alert(a[1]) // All odd numbers<br><br>var b=arr.all(function(x){return x%2==0}) //Check whether all elements in the array are even numbers<br>var c=arr.any (function(x){return x%2==0}) //Check if there is an even number in the array<br>alert(b) <br>alert(c) <br><br></script>

Array.prototype.grep = function(regex,f)

Use the given regular expression to match each element in the array,
Return an array for the matching elements , of course, if there is a function f, the matching result will also be processed by the function f

if (!Array.prototype.push){ // It seems that the push() method is not supported below ie5.0
Array.prototype.push=function(){
for(var i=0;i this [this.length] = arguments[i];
}
           return this.length; >


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