javascript 返回数组中不重复的元素

这是实现结构伪类type-of-type的部分代码：
<script type="text/javascript"> var ret= ["span","span","strong","span","b"] var norepeat = function(array){ var set = array.join(",")+","; while(array.length){ var el = array.shift(); set = set.replace(el+",",""); if(set.indexOf(el+",") != -1){ set = set.replace(new RegExp(el+",","g"),""); array = set.replace(/,$/g,"").split(","); }else{ set = el+","+set; } } return set.replace(/,$/g,"").split(",") } alert(norepeat(ret))//最后返回b,strong </script>
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觉得效果不高，向无忧高手求救。下面是客服果果的(好强大的正则替换啊)：
<script language="javascript"> var ret= ["span","span","strong","span","b"]; var norepeat=function (x) { var y='c0cb5f0fcf239ab3d9c1fcd31fff1efc'; return x.sort().join(y).replace(RegExp('(.*('+y+'|$))\\1+','g'),'').split(y); }; alert(norepeat(ret)); </script>
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abcdreamer 的实现（此实现能过滤非纯字符串数组里的重复，我比较喜欢）：
<script language="javascript"> var a = ["span","span","strong","span","b"]; function norepeat(a) { var i = a.length, j, b; while (i--) { j = i; b = false; while (j--) { if (a[i] === a[j]) { a.splice(j, 1); i--; b = true; } } if (b) a.splice(i, 1); } return a; } alert(norepeat(a)); </script>
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哪位高手有更好的实现，请告诉我一声！
看来有些人不明白norepeat函数与unique函数的区别，norepeat是去除数组中重复的元素，如果数组中有两个a，则去除这两个，unique则会去除其中之一。下面是unique函数的实现：
<script language="javascript"> Array.prototype.inArray = function(el){ for (var i=0,n=this.length;i<n;i++ ) if(this[i]===el)return true; return false; } Array.prototype.unique = function() { var i = 0, n = this.length,ret = []; for (; i < n; i++) if (!ret.inArray(this[i])) ret.push(this[i]); return ret; }; var ret= ["span","span","strong","span","b"] alert(ret.unique()) //返回"span","strong","b" </script>
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