Removing duplicated element from array (utilizing Object) - Javascript -

function removeduplicate(num){   var out=[];   var obj={};    (x = 0; x < num.length; x++){     obj[num[x]]=0;   }   (x in obj){     out.push(x);   }   return out; } var thenum = [1,1,2,3,3,3,4,4,5,6,7,7,7]; result = removeduplicate(thenum);  alert(thenum); alert(result); 

hi everyone, i'm new programming , can't figure out how solution works, sounds me it's assigning zero's object every elements in array...?

and each x in object, insert them array?... values x's carry @ point?

thank helps

here need understand part:

for (x = 0; x < num.length; x++){   obj[num[x]]=0; } 

num[x] have repeated values everytime duplicate value comes overwrites same value again. example:

in 1st iteration:

obj[num[x]] = obj[num[0]] = obj[1] = 0; 

in 2nd iteration:

obj[num[x]] = obj[num[1]] = obj[1] = 0; //since num[1] again 1; 

and on.

so in both above iteration overwriting same value. hence loop results in :

obj = {        1 : 0,        2 : 0,        3 : 0,        4 : 0,        5 : 0,        6 : 0,        7 : 0       } 

then in next loop extract keys(1,2,..) , return it:

for (x in obj){   out.push(x);//push keys 1,2,3... }  return [1,2,3...]//out