js去除数组重复项,删除重复数据的方法

var arr = [3,3,1,6,7,4,4,1];
var o = {};
for(var i = 0; i < arr.length; i++)
{
  o[arr[i]] = arr[i];
}
arr = [];
for (var el in o)
{
  if (el == o[el])
  arr.push(el - 0);
}
alert(arr);

 

var clearRepeat=function(a){
            var c=[],b={};

            for(var i=0;i<a.length;i++){
                    if( ! b[0+a[i]]){
                            b[a[i]]=1;
                            c.push(a[i])
                        }
                }
            return c;
        }

    var a=[undefined,4,5,6,7,8,9,10,11,"aa","bb","aa","bb","$#@@","!*&^%%","$#@@","!*&^%%",0,"0"];
    //请注意上面数组的0,"0"项目。是可以正常处理的。因为他们的数据类型不一样所以他不能算是重复项

    var c=clearRepeat(a);
    alert(c.join())

 

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());

Array.prototype.unique = function(){
    var o = {}, re = [];
    for(var i=0, len = this.length;i<len; i++){
        if(!o[this[i]]){
            o[this[i]] = true;
            re.push(this[i]);
        }
    }
    return re;
}
var arr = [1,2,3,2,3,4,1,2,3,1,1,1,5,6];

console.log( arr.unique() );

 

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);