Linked Questions
38 questions linked to/from Is there a better way to do optional function parameters in JavaScript?
2689
votes
30
answers
1.5m
views
Set a default parameter value for a JavaScript function
I would like a JavaScript function to have optional arguments which I set a default on, which get used if the value isn't defined (and ignored if the value is passed). In Ruby you can do it like this:
...
- 49k
383
votes
2
answers
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views
How can I declare optional function parameters in JavaScript? [duplicate]
Can I declare default parameter like
function myFunc( a, b=0)
{
// b is my optional parameter
}
in JavaScript?
- 5,350
3
votes
4
answers
28k
views
Javascript : optional parameters in function [duplicate]
Let's say I have this :
function concatenate(a, b, c) {
// Concatenate a, b, and c
}
How do I handle those calls ?
x = concatenate(a)
x = concatenate(a, b)
x = concatenate(a, c)
How can I ...
user4676340
3
votes
1
answer
4k
views
Javascript: check if variable is false or if it doesn't exist at all [duplicate]
I want to write a function that uses argument value. If argument does not exist it will use value true by default.
var check = function(truthValue){
var val = truthValue || true;
console.log(...
- 4,201
2
votes
2
answers
315
views
javascript: define a variable in a function [duplicate]
In PHP I can do something like this:
public myFunction($variable=0) {
//Do some stuff
}
In Javascript, the following does not work:
var myFunction = function(variable=0 )
{
//do some stuff.....
- 6,193
0
votes
2
answers
423
views
JS if not a variable [duplicate]
so I want to write a function that takes 3 parameters, 3rd one being optional. I want something to check that if optional does not exist then give it a default value. IS there a IF Not way of doing it?...
- 1,785
0
votes
5
answers
177
views
how to add a default value to a javascript function variable? [duplicate]
Possible Duplicate:
Is there a better way to do optional function parameters in Javascript?
Default value for function parameter?
I can I do this on javascript (jQuery) function
function ...
- 3,162
-1
votes
2
answers
349
views
Write a JavaScript function that changes behavior based on optional arguments [duplicate]
I want to write a function that takes an optional argument and changes its behavior depending on whether or not that argument is provided. This is the first way I thought to do this:
function foo(...
- 5,076
1
vote
2
answers
114
views
Do you have to give all parameters when firing a function in Javascript? [duplicate]
I'm building a little click game with HTML, css and Javascript and I don't think this question belongs in the Game Dev section but here.
I've a a function to put a title and a text in a message box ...
- 42
0
votes
3
answers
73
views
Default vars in a method? [duplicate]
Here's my method:
p.show = function(message, status, timer){
//do stuff
};
Is there a way, so that if vars such as timer are not passed in, to have a default for them, e.g, true.
In php I would ...
- 24.2k
0
votes
2
answers
71
views
In JS what does processMethod = processMethod || function(){}; do? [duplicate]
I am reading through some javascript code, and I have seen a lot of code that looks like this:
processMethod = processMethod || function(){};
it's usually found inside a function. I believe it's a ...
user1214678
0
votes
2
answers
67
views
How to handle optional parameters in function [duplicate]
I have a function named test which accepts two parameters. If any pass any input to that function, it works perfect. But I have a scenario where input may or may not come. How to handle such scenario. ...
- 559
3373
votes
69
answers
2.1m
views
How can I merge properties of two JavaScript objects?
I need to be able to merge two (very simple) JavaScript objects at runtime. For example I'd like to:
var obj1 = { food: 'pizza', car: 'ford' }
var obj2 = { animal: 'dog' }
obj1.merge(obj2);
//obj1 ...
598
votes
23
answers
914k
views
How can you use optional parameters in C#?
Note: This question was asked at a time when C# did not yet support optional parameters (i.e. before C# 4).
We're building a web API that's programmatically generated from a C# class. The class has ...
- 22.8k
316
votes
12
answers
213k
views
What does the construct x = x || y mean?
I am debugging some JavaScript and can't explain what this || does:
function (title, msg) {
var title = title || 'Error';
var msg = msg || 'Error on Request';
}
Why is this guy using var title =...
- 20.8k