js Array对象的扩展函数代码_javascript技巧

使用

复制代码 代码如下:

复制代码 代码如下:

if (!Array.prototype.every)
{
  Array.prototype.every = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i     {
      if (i in this &&
          !fun.call(thisp, this[i], i, this))
        return false;
    }

    return true;
  };
}
if (!Array.prototype.filter)
{
  Array.prototype.filter = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var res = new Array();
    var thisp = arguments[1];
    for (var i = 0; i     {
      if (i in this)
      {
        var val = this[i]; // in case fun mutates this
        if (fun.call(thisp, val, i, this))
          res.push(val);
      }
    }

    return res;
  };
}
if (!Array.prototype.forEach)
{
  Array.prototype.forEach = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i     {
      if (i in this)
        fun.call(thisp, this[i], i, this);
    }
  };
}
if (!Array.prototype.map)
{
  Array.prototype.map = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var res = new Array(len);
    var thisp = arguments[1];
    for (var i = 0; i     {
      if (i in this)
        res[i] = fun.call(thisp, this[i], i, this);
    }

    return res;
  };
}
if (!Array.prototype.some)
{
  Array.prototype.some = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i     {
      if (i in this &&
          fun.call(thisp, this[i], i, this))
        return true;
    }

    return false;
  };
}
Array.prototype.sortNum = function() {
   return this.sort( function (a,b) { return a-b; } );
}

Array.prototype.find = function(searchStr) {
  var returnArray = false;
  for (i=0; i    if (typeof(searchStr) == 'function') {
      if (searchStr.test(this[i])) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    } else {
      if (this[i]===searchStr) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    }
  }
  return returnArray;
}
//随机改变数组的排序
Array.prototype.shuffle = function (){  
    for(var rnd, tmp, i=this.length; i; rnd=parseInt(Math.random()*i), tmp=this[--i], this[i]=this[rnd], this[rnd]=tmp); 
 return this;
}  

Array.prototype.compare = function(testArr) {
    if (this.length != testArr.length) return false;
    for (var i = 0; i         if (this[i].compare) {
            if (!this[i].compare(testArr[i])) return false;
        }
        if (this[i] !== testArr[i]) return false;
    }
    return true;
}
//去掉数组中重复的值var a = new Array("5","7","7"); a.unique();
Array.prototype.unique = function() {
 var data = this || [];
    var a = {}; //声明一个对象，javascript的对象可以当哈希表用
    for (var i = 0; i         a[data[i]] = true;  //设置标记，把数组的值当下标，这样就可以去掉重复的值
    }
    data.length = 0;

    for (var i in a) { //遍历对象，把已标记的还原成数组
        this[data.length] = i;
    }
    return data;
}

Array.prototype.addAll = function($array)
{
 if($array == null || $array.length == 0)
  return;

 for(var $i=0; $i  this.push($array[$i]);
}

Array.prototype.contains = function($value)
{
 for(var $i=0; $i {
  var $element = this[$i];
  if($element == $value)
   return true;
 }

 return false;
}

Array.prototype.indexOf = function($value)
{
 for(var $i=0; $i {
  if(this[$i] == $value)
   return $i;
 }

 return -1;
}
if (!Array.prototype.lastIndexOf)
{
  Array.prototype.lastIndexOf = function(elt /*, from*/)
  {
    var len = this.length;

    var from = Number(arguments[1]);
    if (isNaN(from))
    {
      from = len - 1;
    }
    else
    {
      from = (from            ? Math.ceil(from)
           : Math.floor(from);
      if (from         from += len;
      else if (from >= len)
        from = len - 1;
    }

    for (; from > -1; from--)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}
Array.prototype.insertAt = function($value, $index)
{
 if($index   this.unshift($value);
 else if($index >= this.length)
  this.push($value);
 else
  this.splice($index, 0, $value);
}
/**
* 根据数组的下标来删除元素
*/ 
Array.prototype.removeByIndex=function($n) {　 
    if($n    　　return this; 
    }else{ 
        return this.slice(0,$n).concat(this.slice($n+1,this.length)); 
    } 
}
//依赖indexOf
Array.prototype.remove = function($value)
{
 var $index = this.indexOf($value);

 if($index != -1)
  this.splice($index, 1);
}

Array.prototype.removeAll = function()
{
 while(this.length > 0)
  this.pop();
}

Array.prototype.replace = function($oldValue, $newValue)
{
 for(var $i=0; $i {
  if(this[$i] == $oldValue)
  {
   this[$i] = $newValue;
   return;
  }
 }
}

Array.prototype.swap = function($a, $b)
{
 if($a == $b)
  return;

 var $tmp = this[$a];
 this[$a] = this[$b];
 this[$b] = $tmp;
}
Array.prototype.max = function() { 
 return Math.max.apply({}, this); 
} 
Array.prototype.min = function() { 
 return Math.min.apply({}, this); 
}
Array.prototype.splice = function(start, delLen, item){
 var len =this.length;
 start = startlen?len:start?start:0;
 delLen=delLenlen?len:delLen?delLen:len; 

 var arr =[],res=[];
 var iarr=0,ires=0,i=0;

 for(i=0;i  if(i=delLen) arr[iarr++]=this[i];
  else {
   res[ires++]=this[i];
   if(item&&ires==delLen){
    arr[iarr++]=item;
   }
  } 
 }
 if(item&&ires
 for(var i=0;i  this[i]=arr[i];
 }
 this.length=arr.length;
 return res;
}
Array.prototype.shift = function(){ if(!this) return[];return this.splice(0,1)[0];}

//分开添加,关键字shallow copy,如果遇到数组，复制数组中的元素
Array.prototype.concat = function(){
 var i=0;
 while(i  if(typeof arguments[i] === 'object'&&typeof arguments[i].splice ==='function' &&!arguments[i].propertyIsEnumerable('length')){
  // NOT SHALLOW COPY BELOW
  // Array.prototype.concat.apply(this,arguments[i++]);
   var j=0;
   while(j   i++;
  } else{
   this[this.length]=arguments[i++];
  }
 }
 return this;
}

Array.prototype.join = function(separator){
 var i=0,str="";
 while(i return str;
}

Array.prototype.pop = function() { return this.splice(this.length-1,1)[0];}

Array.prototype.push = function(){
 Array.prototype.splice.apply(this,
  [this.length,0].concat(Array.prototype.slice.apply(arguments))); //这里没有直接处理参数，而是复制了一下
 return this.length;
}
Array.prototype.reverse = function(){
 for(var i=0;i  var temp = this[i];
  this[i]= this[this.length-1-i];
  this[this.length-1-i] = temp;
 }
 return this;
}
Array.prototype.slice = function(start, end){
 var len =this.length;
 start=start end =endlen?len:end?end:len;

 var i=start;
 var res = [];
 while(i  res.push(this[i++]);
 }
 return res; 
}
//arr.unshift(ele1,ele2,ele3....)
Array.prototype.unshift =function(){
 Array.prototype.splice.apply(this,[0,0].concat(Array.prototype.slice.apply(this,arguments)));
}