Javascript set(-of-string) functions - JavaScript Snipplr Social Repository

Revision: 7285

at July 17, 2008 06:33 by scarfboy

Updated Code

function unique(l) {
  var o=new Object(),ret=[];
  for(i in l){o[l[i]]=1}
  for(k in o){ret.push(k)}
  return ret;
}
 
function union(l1,l2) {
  var o=new Object(),ret=[];
  for(i in l1){o[l1[i]]=1}
  for(i in l2){o[l2[i]]=1}
  for(k in o){ret.push(k)}
  return ret;
}
 
function intersect(l1,l2) {
  var o=new Object(), ret=[];
  for (i in l1) o[l1[i]]=1; //this value is ignored 
  for (i in l2)
    if (o[l2[i]]!==undefined)
       ret.push(l2[i]);
  return ret;
}
 
function except(l1,l2) {
  var o=new Object(), ret=[];
  for (i in l1) o[l1[i]]=1;
  for (i in l2) delete(o[l2[i]]);
  for (i in o) ret.push(i);
  return ret;
}

Revision: 7284

at July 17, 2008 06:31 by scarfboy

Initial Code

//Unique-ify list. (set-in-list)
function unique(l) {
  var o=new Object(),ret=[];
  for(i in l){o[l[i]]=1}
  for(k in o){ret.push(k)}
  return ret;
}
 
function union(l1,l2) {
  var o=new Object(),ret=[];
  for(i in l1){o[l1[i]]=1}
  for(i in l2){o[l2[i]]=1}
  for(k in o){ret.push(k)}
  return ret;
}
 
function intersect(l1,l2) {
  var o=new Object(), ret=[];
  for (i in l1) o[l1[i]]=1; //the value is ignored 
  for (i in l2)
    if (o[l2[i]]!==undefined)
       ret.push(l2[i]);
  return ret;
}
 
function except(l1,l2) {
  var o=new Object(), ret=[];
  for (i in l1) o[l1[i]]=1;
  for (i in l2) delete(o[l2[i]]);
  for (i in o) ret.push(i);
  return ret;
}

Initial URL

Initial Description

Exploits hash keys uniqueness, but in doing so effectively toString()s everything, meaning this should not be used for much beyond strings and perhaps integers.

I used this when I wanted to do some client-side filtering of (integer) identifiers.

Initial Title

Javascript  set(-of-string) functions

Initial Tags

javascript

Initial Language

JavaScript

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