js删除数组中重复的值

例如：var student = [‘qiang','ming','tao','li','liang','you','qiang','tao'];
第一种思路是：遍历要删除的数组arr, 把元素分别放入另一个数组tmp中，在判断该元素在arr中不存在才允许放入tmp中
用到两个函数：for ...in 和 indexOf()

第二种思路是：把目标数组arr的元素值和键的位置调换 自动就把重复的元素给删除掉了，调换后的样子：array('qiang'=>1,'ming'=>1,'tao'=>1)

js数组中去除重复值
Array.prototype.del = function() { var a = {}, c = [], l = this.length; for (var i = 0; i < l; i++) { var b = this[i]; var d = (typeof b) + b; if (a[d] === undefined) { c.push(b); a[d] = 1; } } return c; } alert([1, 1, 2, 3, 4, 5, 4, 3, 4, 4, 5, 5, 6, 7].del()) [Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]
方法二
复制代码 代码如下:
//去重复数组
function unique(data){
data = data || [];
var a = {};
len = data.length;
for (var i=0; ivar v = data[i];
if (typeof(a[v]) == 'undefined'){
a[v] = 1;
}
};
data.length=0;
for (var i in a){
data[data.length] = i;
}
return data;
}

方法三
复制代码 代码如下:
var arr = ["123","123","123","123","sfsdf","123","345","123","123","345","456","567","sdc"];
var str = [];
for(var i = 0,len = arr.length;i < len;i++){
! RegExp(arr[i],"g").test(str.join(",")) && (str.push(arr[i]));
}
alert(str);

方法四
复制代码 代码如下:
var pureMulti1=function(arr){
var obj={};
var a = [];
for(var i=0,l=arr.length;iif(!((arr[i]+"") in obj)){
a.push(arr[i]);
}
obj[arr[i]]="";
}
return a;
}