TypeError in Javascript

Question

function url_info()
{
    var url_val=document.getElementsByClassName("spc-tab");
    var current_s=0;
    for(var i=0;i<url_val.length;i++)
    {
        var url_class=url_val[i].className.split(" ");
        if(url_class[1]!=null)
        {
            if(url_class[1]=="selected")
            {
                current_s=i;
                break;
            }
        }
    }
    var temp_1=url_val[current_s].text;          //**Error here**
    return(temp_1);
}

In this function url_info i am getting the TypeError But i don't know why?? .... as My var current_s is defined within the scope and integer...

not sure what an elements text property is supposed to be though! — Jaromanda X
– Jaromanda X, Commented Jul 14, 2018 at 9:33
All of this code can be reduced to document.querySelector(".spc-tab.selected").textContent;. — Sebastian Simon
– Sebastian Simon, Commented Jul 14, 2018 at 9:37
@Lokesh "so . won't work here" - What?? that makes absolutely zero sense ... your point was that it was an array ... it isn't — Jaromanda X
– Jaromanda X, Commented Jul 14, 2018 at 9:42
so, document.getElementsByClassName("spc-tab") is returning an empty HTMLCollection ... which is why you get the error ... you're probably calling url_info before any elements with that class exist - which is a common error, trying to run javascript before the page loads — Jaromanda X
– Jaromanda X, Commented Jul 15, 2018 at 0:36

Ullas Hunka · Accepted Answer · 2018-07-14 10:00:05Z

1

why write this much of code when one line can do:

function url_info() {
  var temp_1 = "";
  var url_val = document.querySelector(".spc-tab.selected");

  temp_1 = url_val[0].text > 0 ? url_val[0].text : temp_1; 
  return (temp_1);
}

and second, you don't require to convert your class name to string then split. You just can access them through classlist. Then use contains.

function url_info() {
  var url_val = document.getElementsByClassName("spc-tab");
  var current_s = 0;
  for (var i = 0; i < url_val.length; i++) {
    var isSelected = url_val[i].classList.contains("selected");
    if (isSelected) {
      current_s = i;
      break;
    }
  }
  var temp_1 = url_val[current_s].text; 
  return (temp_1);
 }

edited Jul 14, 2018 at 10:00

answered Jul 14, 2018 at 9:53

Ullas Hunka

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1 Comment

adarsh Over a year ago

I don't Know why My code is not working in Html file ...... it is working fine when I am adding it in console ..But in Html file it gives error and it is showing me url_val correct ... but after that i tried to check url_val.length and it is giving me 0 .... but when I printed the url_val on console same script but with console.log(url_val) it is showing me HtmlCollection with 8 entries....

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