This question already has answers here:
Javascript object bracket notation ({ Navigation } =) on left side of assign
(5 answers)
What does this symbol mean in JavaScript?
(1 answer)
Closed 4 years ago.
I can't seem to find anything in the documentation to understand why the { and } characters are wrapped around variables on some examples I've seen. Can anyone example why we would do that?
For example:
const {app} = require('./app/app.js');
Related
This question already has answers here:
Rules for unquoted JavaScript Object Literal Keys?
(6 answers)
What characters are valid for JavaScript variable names?
(12 answers)
Closed 1 year ago.
I am seeing it crop up more and more in code I am going through on a new project (can't share due to contractual reasons) where Ill see something like:
{
prop1: value$ref,
$prop2: null
}
I have see ${prop3} before, but never an example without the brackets. Can anyone provide direction as to what the method is, or the operator is or whatever the case?
This question already has answers here:
What does this symbol mean in JavaScript?
(1 answer)
Javascript object bracket notation ({ Navigation } =) on left side of assign
(5 answers)
Closed 4 years ago.
I've been trying to find out what this notation is called so I can better google it. It's from the gmail api node example but wont run for me.
const {client_secret, client_id, redirect_uris} = credentials.installed;
I think this is the correct stackexchange site for this, but if I'm wrong, happy to relocate it to a more appropriate one.
It is Destructuring Assignment
This question already has answers here:
What do the brackets around the arguments mean when reading documentation for a method? [duplicate]
(3 answers)
How to interpret function parameters in software and language documentation?
(4 answers)
Closed 4 years ago.
I'm looking through the MDN web docs and have seen this parameters for Object
// Object initialiser or literal
{ [ nameValuePair1[, nameValuePair2[, ...nameValuePairN] ] ] }
However, I'm struggling to understand what I'm actually looking at, I know it's an object literal, but the bracket notation is throwing me
This question already has answers here:
What does "!" operator mean in javascript when it is used with a non-boolean variable?
(5 answers)
What is an exclamation point in JavaScript?
(2 answers)
Closed 5 years ago.
Coming from java, learning angular/typescript: The ! negates booleans or boolean expressions. This is, according to my research, the same in javascript/typescript. But what does the following method do?
isSelected(product: Product): boolean {
if (!product || !this.currentProduct) {
return false;
}
return product.sku === this.currentProduct.sku;
}
What is !product? Product is coming in as a method parameter and then it is asked, if product is not product, or wtf should that mean? :D
This question already has answers here:
What do square brackets around an expression mean, e.g. `var x = a + [b]`?
(7 answers)
Closed 7 years ago.
function construct(head, tail) {
return cat([head], _.toArray(tail));
}
I'd like to know the role of '[' and ']' above.
Is it an operator?
Is it the array initialize literal?
This question is answered here and on the previous QnA(Use of [square brackets] around JavaScript variables).
I felt this weird because I am not used to javascript.
But this is not a matter any more.
I thought wrong and this is explained. Thanks!
It is initializing a 1 element array to pass to cat here. Brackets can be used to access elements on objects and arrays, and to represent an array literal like you have here.