Javascript Data Type How to - Remove Objects to keep unique key within an array

Question

We would like to know how to remove Objects to keep unique key within an array.

Answer


<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
<!--   w  w w . ja v  a 2 s .  co  m-->
var a = [
  { id:"123", url:"example1.com"},
  { id:"123", url:"example2.com"},
  { id:"456", url:"example3.com"},
  { id:"789", url:"example4.com"},
];
var b = [];
var t = {};
for(var i = 0; i < a.length; i++){
    if(t[a[i].id]){
        continue;
    }
    t[a[i].id] = true;
    b.push(a[i]);
}
document.writeln(JSON.stringify(b));

</script>
</head>
<body>
</body>
</html>

The code above is rendered as follows: