I am using ternary expression to check if the variable exists to display value accordingly, but since, I need to check both if it exists and that is has some values in it, it fails on checking the condition when the variable is undefined. How can I fix that?
This is the code:
$('#select').selectize({
items: typeof icoop != "undefined" && icoop != null || icoop.selectedUsers.length < 1 ? icoop.selectedUsers : []
});
I get:
Uncaught ReferenceError: icoop is not defined
icoop is undefined, so accessing any property or function will fail.
Check for icoop before checking for icoop.selectedUsers:
$('#select').selectize({
items: (typeof icoop !== 'undefined' && icoop && icoop.selectedUsers && icoop.selectedUsers.length > 0) ? icoop.selectedUsers : []
});
You may also clean up the code a little bit:
// Check for icoop existence. Assign a default value if it is undefined or null.
var icoop = (typeof icoop !== 'undefined' && icoop) || {};
$('#select').selectize({
items: (Array.isArray(icoop.selectedUsers) && icoop.selectedUsers) || []
});
Try
items: icoop != undefined && typeof icoop.selectedUsers != "undefined" &&...
also check out How to check for "undefined" in JavaScript?
icoop is encountered if there is no such variable declared
typeof icoop != "undefined"is false, which makes the entire AND condition also false but then you are left with, essentially,false || ( icoop.selectedUsers.length < 1 ? icoop.selectedUsers : [] )and because this is an OR, the evaluation will continue on the right, where the error occurs.