js Array对象的扩展函数代码

Jenna ·

更新时间:2024-11-10

· 835 次阅读

使用

代码如下:
<script language=javascript>
var isNumeric = function(x) {
   // returns true if x is numeric and false if it is not.
   var RegExp = /^(-)?(\d*)(\.?)(\d*)$/;
   return String(x).match(RegExp);
}
var myArray = [1,'two',3,'four',5,'six',7,'eight',9,'ten'];
var oddArray=myArray.filter(isNumeric); // outputs: 1,3,5,7,9
var oddArray=myArray.some(isNumeric); // outputs: true
var oddArray=myArray.every(isNumeric); // outputs: false
var printArray =function(x, idx){
   document.writeln('['+idx+'] = '+x);
}
myArray.forEach(printArray);// outputs: [0] = 1 [1] = two [2] = 3 [3] = four [4] = 5
myArray.remove(9);
document.writeln(myArray);

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 < len; 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 < len; 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 res = new Array(len);
    var thisp = arguments[1];
    for (var i = 0; i < len; 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 < len; 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<this.length; 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 < testArr.length; 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 < data.length; 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; $i<$array.length; $i++)
this.push($array[$i]);
}

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

return false;
}

Array.prototype.indexOf = function($value)
{
for(var $i=0; $i<this.length; $i++)
{
if(this[$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 < 0)
           ? Math.ceil(from)
           : Math.floor(from);
      if (from < 0)
        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 < 0)
  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($n<0){　//如果n<0，则不进行任何操作。
    　　return this;
    }else{
        return this.slice(0,$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<this.length; $i++)
{
  if(this[$i] == $oldValue)
  {
   this[$i] = $newValue;
   return;
  }
}
}

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

//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<arguments.length){
  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<arguments[i].length) this.splice(this.length,0,arguments[i][j++]);
   i++;
  } else{
   this[this.length]=arguments[i++];
  }
}
return this;
}

Array.prototype.join = function(separator){
var i=0,str="";
while(i<this.length) str+=this[i++]+separator;
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<this.length/2;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<0?start+=len:start?start:0;
end =end<0?end+=len:end>len?len:end?end:len;
var i=start;
var res = [];
while(i<end){
  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)));
}