Questions tagged [function-expression]
100 questions
3
votes
1 answer
function expression on firefox - not expected result
if (true) {
function foo(){ return 1; }
}
else {
function foo(){ return 2; }
}
foo();
The above code is an example of function expression and returns 1 in Firefox 28 whereas 2 in Chrome ( expected result). Why is firefox giving wrong result ?
Vivek Chandra
- 4,240
- 9
- 33
- 38
3
votes
1 answer
Javascript: Define variable as anonymous function that calls the same function
I am given a function like this:
//! Work on record.
/*!
\param[in] Record (object) Record.
\param[in] AsyncCallback (function) Asynchronous callback which is called when the operation is complete. It takes no…
Pang
- 9,564
- 146
- 81
- 122
2
votes
2 answers
When we should use class expression in Javascript?
I have recently got to know that we do have class expressions too like function expressions in JS. I know some points about it(MDN) like:
Class expressions may omit the class name ("binding identifier"), which is not possible with class…
Apoorva Chikara
- 8,277
- 3
- 20
- 35
2
votes
1 answer
How do you check for null or undefined on a variable assigned to a missing anonymous function expression?
When commenting out the anonymous function expression "a" below, how do you properly check for NULL on "b"? Use case: Lets say "a" is an in-page JS include (library) that is assigned to "b", but the library failed to load and now we have a console…
Cody Tolene
- 127
- 1
- 1
- 10
2
votes
1 answer
Reference to an object's array from within the object in Javascript
I would like to create a new object of the type InvertedPeninsula:
var invertedPeninsula = new InvertedPeninsula();
To create this object type, I use an object constructor function:
var InvertedPeninsula = function() {
this.inhabitants = [
…
Dean P
- 1,841
- 23
- 23
2
votes
1 answer
How to prevent JS minification from removing names of named-function-expressions?
I have this function on an object that I need to trace REALLY BADLY, along with the parent caller of the invocation and arguments passed to the caller.
This well works until minified:
var foo = {
FunctionToBeLogged: function GiveMeAName() {
…
Fernando Espinosa
- 4,625
- 1
- 30
- 37
2
votes
3 answers
What is the preferred way to use a Javascript function expression?
I've seen these different patterns when calling a JavaScript function expression:
Pattern #1
var global = function () {
return this;
}();
Pattern #2
var global = (function () {
return this;
}());
Pattern #3
var global = (function () {
…
dalembertian
- 23
- 5
1
vote
3 answers
Passing a function expression to be used as onclick handler for a button
For a button, I need to set the function this calls, and the value used in that call, at runtime.
I can do this like so:
var myfunction = /* ... */
var myvalue = /* ... */
button.setAttribute ("onclick", myfunction + "('" + myvalue + "')");
If I…
gzost
- 2,375
- 1
- 18
- 25
1
vote
1 answer
Can You Implement Javascript Class Via Function Expression?
I was tackling this question in leet code:
Implement the MapSum class:
MapSum() Initializes the MapSum object. void insert(String key, int
val) Inserts the key-val pair into the map. If the key already
existed, the original key-value pair will be…
maddie
- 1,854
- 4
- 30
- 66
1
vote
2 answers
What is the difference between 'let' and 'this' in JavaScript?
I'm learning JavaScript, coming from Ruby, have done some stuff in C as well. One example in my reading is:
function letCounter() {
let counter = 0;
return () => ++counter;
}
and is compared to
function thisCounter() {
this._count =…
Aaron Parisi
- 464
- 7
- 15
1
vote
1 answer
Console output sequence sometimes does not match with the sequence in which they are called
I am new to JavaScript and this is my first question on
Stackoverflow, please let me know if I missed something which
should be included in the question.
Question 1:
Can anyone explain why sometimes the console output sequence does not match…
AtlasUser5
- 81
- 6
1
vote
4 answers
How to use function expression values in other functions?
I'm learning Javascript and I make a rock, scissors, paper project. I already make it work with the sample code but now I want to use a function expression to use its value in other functions. When I load the code it gave me undefined and I don't…
user12114366
1
vote
1 answer
Why Named Function Expression itself cannot assign Name to another Value?
var functionVariable = function functionExpressionName() {
functionExpressionName = 1;
console.log(functionExpressionName) // function
};
functionVariable();
If You run this example you can see we can not reassign to functionExpressionName…
Murad Sofiyev
- 790
- 1
- 8
- 25
1
vote
1 answer
JS Class: Difference between ES6 myFunc(){..} and ES5 myFunc = function() {...} in a class declaration
In the following code,
class PersonClass {
constructor(fname) {
this.fname = fname;
}
read = function() { console.log('I am reading') }
speak () { console.log('I am speaking'); }
}
//Instantiate
let p1 = new PersonClass('Raj')
read…
appu
- 471
- 1
- 8
- 26
1
vote
0 answers
Assigning arrow function as the default value with ||
So I was writing a function which would take an argument(another function), which when undefined would be assigned a default value. Assigning that default value as an ()=>{} does not seem to work.
However when I wrap the default function in (()=>{})…
A Rogue Otaku
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