1 /*Array对象构造函数*/ 2 ?3 ????/*组合记忆 shift unshift pop push 4 ????添加和删除 5 ????shift unshift ?从数组开头开始添加或者删除 6 ????pop push ??从数组末尾添加或者删除 7 ?????*/ 8 ?9 ????//shift：删除原数组第一项，并返回删除元素的值；如果数组为空则返回undefined10 ????var arr1 = [1,2,3,4,5];11 ????var arr2 = [1,2,3,4,5];12 ????var result = arr1.shift(); 13 ????console.log(result);//a：[2,3,4,5] b：114 15 ????//unshift：将参数添加到原数组开头，并返回数组的长度16 ????arr1 = [1,2,3,4,5];17 ????result = arr1.unshift(-2,-1); 18 ????console.log(result);//a：[-2,-1,1,2,3,4,5] b：719 ????//注：在IE6.0下测试返回值总为undefined，20 ????//FF2.0下测试返回值为7，所以这个方法的返回值不可靠，需要用返回值时可用splice代替本方法来使用。21 22 23 ????//pop：删除原数组最后一项，并返回删除元素的值；如果数组为空则返回undefined24 ????arr1= [1,2,3,4,5];25 ????result = arr1.pop(); 26 ????console.log(result);//a：[1,2,3,4] b：527 28 ????//push：将参数添加到原数组末尾，并返回数组的长度29 ????arr1 = [1,2,3,4,5];30 ????result = arr1.push(6,7); 31 ????console.log(result);//a：[1,2,3,4,5,6,7] b：7

1 /*数组合并concat*/2 3 ????//concat：返回一个新数组，是将参数添加到原数组中构成的4 ????arr1 = [1,2,3,4,5];5 ????result = arr1.concat(6,7); 6 ????console.log(result);//a：[1,2,3,4,5] b：[1,2,3,4,5,6,7]

 1 /*排序 sort 从小到大 reverse 从大到小*/ 2 ?????// sort(orderfunction)：按指定的参数对数组进行排序 3 ????arr1 = [1,2,3,4,5]; 4 ????result = arr1.sort(); ?5 ????console.log(result);//[1,2,3,4,5] 6 ?7 ????// ???reverse：将数组反序 8 ????arr1 = [1,2,3,4,5,8,34]; 9 ????result = arr1.reverse(); 10 ????console.log(result);//[34,8,5,4,3,2,1]

1 // slice(start,end)：返回从原数组中指定开始下标到结束下标之间的项组成的新数组，但不包括结束位置的项2 ????arr1 = [1,2,3,4,5];3 ????result = arr1.slice(2,5); //[3,4,5]4 ????result = arr1.slice(2); ??//[3,4,5] ????在只有一个参数的情况下，slice()方法返回从该参数指定位置开始到当前数组末尾的所有项；5 6 ????//返回自身7 ????result = arr1.slice(0); ??//返回自身

1 /*join(separator) 数组拼接成字符串*/2 ????//将数组的元素组起一个字符串，以separator为分隔符，省略的话则用默认用逗号为分隔符3 ????arr1 = [1,2,3,4,5];4 ????result = arr1.join("|"); //a：[1,2,3,4,5] b："1|2|3|4|5"

 1 /*splice*/ 2 ????//splice(start,deleteCount,val1,val2,...)： 3 ????// 从start位置开始删除deleteCount项，并从该位置起插入val1,val2,... 4 ????arr1 = [1,2,3,4,5]; 5 ????result = arr1.splice(2,2,7,8,9); //a：[1,2,7,8,9,5] b：[3,4] 6 ????result = arr1.splice(0,1); //同shift 7 ?8 ????arr1.splice(0,0,-2,-1); 9 ????result = arr1.length; //同unshift10 11 ????result = arr1.splice(arr1.length-1,1); //同pop12 ????arr1.splice(arr1.length,0,6,7);13 ????result = arr1.length; //同push

 1 <script> 2 ????/*--数组扩展方法--*/ 3 ????/* 4 ?????*去除数组中的重复项 5 ?????*/ 6 ????Array.prototype.unique = function() { 7 ????????var a = []; var l = this.length; 8 ????????for (var i = 0; i < l; i++) 9 ????????{10 ????????????for (var j = i + 1; j < l; j++)11 ????????????{12 ????????????????if (this[i] === this[j]) j = ++i;13 ????????????}14 ????????????a.push(this[i]);15 ????????}16 ????????return a;17 ????};18 19 ????var arr = [1,2,3,4,5,6,6,7,7,77,7,]20 ????console.log(arr.unique());//Array(8)21 22 </script>