Assign empty string to javascript variable

Question

I get return value as null and assign that value it shows as null in the UI. But I want to check some condition and if it is null, it should not show up anything.. I tried the below code and it doesn't work

 var companyString; if(utils.htmlEncode(item.companyname) == null) { companyString = ''; } else{ companyString = utils.htmlEncode(item.companyname); } 

Answer 1

Compare item.companyname to null (but probably really any false-y value) - and not the encoded form.

This is because the encoding will turn null to "null" (or perhaps "" , which are strings) and "null" == null (or any_string == null ) is false.

Using the ternary operator it can be written as so:

var companyString = item.companyname
  ? utils.htmlEncode(item.companyname)
  : "";

Or with coalescing:

var companyString = utils.htmlEncode(item.companyname ?? "");

Or in a long-hand form:

var companyString;
if(item.companyname) // if any truth-y value then encode
{
  companyString = utils.htmlEncode(item.companyname);
}
else{                // else, default to an empty string
  companyString = '';
}

Answer 2

var companyString="";
if(utils.htmlEncode(item.companyname) != null)
{
   companyString = utils.htmlEncode(item.companyname);
}

Answer 3

var companyString;
if(item.companyname !=undefined &&   item.companyname != null ){
companyString = utils.htmlEncode(item.companyname);  
}
else{
companyString = '';
}

Better to check not undefined along with not null in case of javascript. And you can also put alert or console.log to check what value you are getting to check why your if block not working. Also, utls.htmlEncode will convert your null to String having null literal , so compare without encoding.