Display undefined items in loop as zero

Question

I have an ajax call that creates html elements based on a loop. Some of the data in my call is empty and will display as undefined, I am trying to find a way to have it display as zero.

success: function(response) {
    var results = response.results;
    var html = '';

    for (var i = 0; i < results.length; i++){
         html += '<span class="test">' + results[i].code + '</span>'
     }
}
$('#mydiv').html(html);

The above code would display like this.

123
456
undefined
678
undefined

How can i suppress the undefined to print like

if( results[i].code ===undefined){ 0 } – JYoThI May 23 '17 at 16:46 — JYoThI, May 23 '17 at 16:46

score 1 · Accepted Answer · answered May 23 '17 at 16:47

1

you can try (results[i].code == null)

success: function(response) {
    var results = response.results;
    var html = '';

    for (var i = 0; i < results.length; i++){
         var ht = (results[i].code == null)? 0 : results[i].code;
         html += '<span class="test">' + ht  + '</span>'
     }
}
$('#mydiv').html(html);

Ref : How to determine if variable is 'undefined' or 'null'?

answered May 23 '17 at 16:47

Mohamed-Yousef

23,946
3
19
28

This is close to what I was trying to do. Thank you – user2168066 May 23 '17 at 16:50

score 0 · Answer 2 · answered May 23 '17 at 16:47

0

just use if else

 if( results[i].code ===undefined){

    html += '<span class="test">0</span>';

  }else{

    html += '<span class="test">' + results[i].code + '</span>';
  }

answered May 23 '17 at 16:47

JYoThI

11,977
1
11
26

score 0 · Answer 3 · answered May 23 '17 at 16:52

success: function(response) {
    var results = response.results;
    var html = '';

    for (var i = 0; i < results.length; i++){
         html += '<span class="test">' + ((typeof results[i].code != "undefined") ? results[i].code : 0) + '</span>'
     }
}
$('#mydiv').html(html);

score 0 · Answer 4 · answered May 23 '17 at 16:54

You will need to add a condition to check if the value is undefined (might also be good to check for null values as well) and then display "0" if the value is undefined (or null).

You can update your code to something like this to make sure that your undefined values are printed as "0":

success: function(response) {
    var results = response.results;
    var html = '';

    for (var i = 0; i < results.length; i++){
        var resultCode = results[i].code;
        if (typeof resultCode === "undefined" || resultCode === null){
            resultCode = 0;
        }
        html += '<span class="test">' + resultCode + '</span>'
    }
}
$('#mydiv').html(html);

Display undefined items in loop as zero

4 Answers4