undefined Questions
6
Solved
I have two pages - "page 1" and "page 2". On page 1 there's an text-box with a value of e.g. 100 and a button at the end.
By pressing the button I want javascript to save the value of the textbox ...
Myxomatosis asked 4/1, 2015 at 12:49
7
Solved
I need to declare a type such that removes the undefined from its property types.
Suppose we have:
type Type1{
prop?: number;
}
type Type2{
prop: number | undefined;
}
type Type3{
prop: numb...
Demurral asked 29/10, 2018 at 16:34
10
Solved
Recently I installed node.js on my Windows 7 machine.
On execution of JavaScript, I get an undefined message along with successful execution of the expression.
What's wrong here? I have not not...
Screed asked 10/12, 2011 at 15:2
10
Solved
I have a function which I have written which basically looks like this:
function getNextCard(searchTerms) {
// Setup Some Variables
// Do a bunch of logic to pick the next card based on termed ...
Verticillaster asked 23/6, 2016 at 0:53
3
Uncaught (in promise) TypeError: Cannot convert undefined or null to object
at Function.keys (<anonymous>)
at companion-bubble.js:1465:19726
at Generator.next (<anonymous>)
at Ln (c...
9
Solved
So Safari keeps yelling at me for one specific error.
I'm trying to use Google Maps API and call map.getCenter();. However sometimes, this happens before the map has been fully loaded.
So instead...
Buckman asked 18/5, 2011 at 15:8
39
Solved
What is the difference between null and undefined in JavaScript?
Broadcloth asked 22/2, 2011 at 10:30
4
Solved
When I try to alert a negation of variable having undefined value , I get the output as true?
alert(undefined);
alert(!undefined);
The first alert gives undefined and second alert gives true.
Is...
Rollie asked 22/8, 2016 at 8:55
1
I am trying to access env variables using a .env file in a VueJS 3 project, following the docs of vue 3 and some issues over here, but nothing seems to work.
I already checked, the .env is inside t...
Uella asked 5/3, 2022 at 13:30
2
I'm looking for a way to do undefined coalescing in javascript with booleans. I'm used to doing the following, for, say, positive integers:
var x = i1 || i2 || i3 || i4;
This is a 'slick' way, b...
Jelly asked 25/11, 2015 at 21:46
5
Solved
I am just wondering why it is not possible to make forEach on array of undefined.
Code:
var arr = new Array(5); // [undefined x 5]
//ES5 forEach
arr.forEach(function(elem, index, array) {
conso...
Cyclo asked 4/5, 2014 at 18:59
4
Solved
I know it is one of the constant ask question
so i get this error
'WorldObject': [Base class undefined (translated from german)]
Here is the code which produce this error:
ProjectilObject.h:
#pragm...
3
Solved
So in most cases I've been able to use something similar to these lines, but Javascript has given me this weird result.
If I take some value and it turns out to be undefined, when compared to an i...
Babe asked 2/3, 2014 at 22:28
3
We are upgrading to PHP 8.1. A new feature is that an undefined array key throws a warning.
Unfortunately this interferes with the ability to easily use associative arrays such as $_SESSION v...
Ruelas asked 7/2, 2022 at 20:40
25
Solved
Why is null considered an object in JavaScript?
Is checking
if ( object == null )
Do something
the same as
if ( !object )
Do something
?
And also:
What is the difference between null a...
Bonnet asked 29/4, 2009 at 5:47
9
Solved
The jQuery Core Style Guidelines suggest two different ways to check whether a variable is defined.
Global Variables: typeof variable === "undefined"
Local Variables: variable === undefi...
Whish asked 18/1, 2011 at 15:2
31
Solved
Which method of checking if a variable has been initialized is better/correct?
(Assuming the variable could hold anything (string, int, object, function, etc.))
if (elem) { // or !elem
or
if (type...
Serology asked 25/2, 2011 at 3:44
1
Solved
Derived from Canonical question for TypeError Cannot [call method / read property / set property] of null in Google Apps Script
Proposed reference for questions like :
Why the Execution order of ...
Contractor asked 18/10, 2022 at 9:53
1
Function has a trigger for on form submit
having issues with this very first line. Its supposed to grab data from excel sheet to auto-populate into a copy of template
function autofillGoogleDo...
Mycosis asked 18/10, 2022 at 0:45
5
Solved
I'm facing an issue with the following code.
What it basically should do. It should load and parse a given JSON file. And in the RequestListender it should show the ID and the string Hello which ...
Estate asked 1/12, 2015 at 22:29
5
Solved
What's the best way to check if myvar javascript variable === false or not (it may be undefined as well).
if (myvar === false)
would be fine but myvar could be undefined. Only false value is accep...
Piercy asked 25/9, 2014 at 19:36
3
Solved
In TypeScript, you can annotate a function as returning void:
function fn1(): void {
// OK
}
function fn2(): void {
// Error
return 3;
}
You can also annotate a function to return undefined:...
Kingdon asked 15/11, 2019 at 22:27
1
I have a function basically like this
function foo(): Promise<MyClass | undefined> {
if(somethingGoesWrong) {
return Promise.resolve(undefined);
}
return Promise.resolve(new MyClass());
...
Jampan asked 1/12, 2019 at 3:37
2
Solved
I have a type-class instance like this:
instance {-# OVERLAPPABLE #-} (TypeError ( 'Text "Some error")) => SomeClass x where
someMethod = undefined
This instance exists at the end of...
Prebend asked 27/6, 2022 at 23:13
9
I'm learing JavaScript. I cannot grasp the idea of an empty object. As I understand, there are situations when I need to check a variable whether it holds an object and has a value.
So far, I...
Declaration asked 27/1, 2021 at 19:32
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