js Array对象的扩展函数代码_Javascript教程-查字典教程网
js Array对象的扩展函数代码
js Array对象的扩展函数代码
发布时间:2016-12-30 来源:查字典编辑
摘要:使用复制代码代码如下:varisNumeric=function(x){//returnstrueifxisnumericandfalsei...

使用

复制代码 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);

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 < 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 thisp = arguments[1];

for (var i = 0; i < len; 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 < 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;

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 = start<0?0:start>len?len:start?start:0;

delLen=delLen<0?0:delLen>len?len:delLen?delLen:len;

var arr =[],res=[];

var iarr=0,ires=0,i=0;

for(i=0;i<len;i++){

if(i<start|| ires>=delLen)arr[iarr++]=this[i];

else {

res[ires++]=this[i];

if(item&&ires==delLen){

arr[iarr++]=item;

}

}

}

if(item&&ires<delLen) arr[iarr]=item;

for(var i=0;i<arr.length;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<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)));

}

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