js过滤数组重复元素的方法

function filterArray(str,array){ //此函数为过滤数组中重复的元素,并不允许插入空值,函数返回数组 
var isnull = false; 
if(str == "" || str == null || str == 'undefined'){ 
isnull = true; 
} 
var newnum = 0; 
var newarray = []; 
var num = array.length; 
if(num == 0){ 
if(!isnull){ 
newarray[num] = str; 
} 
}else{ 
for(var m=0;m < num;m++){ 
if(str == array[m]){ 
break; 
}else{ 
newarray[newnum++] = array[m]; 
} 
} 
if(!isnull){ 
newarray[newnum++] = str; 
} 
} 
return newarray; 
}