This question already has answers here:
What are these three dots in React doing?
(23 answers)
Closed 3 years ago.
Piece of code from angularfire in firestore query.
https://github.com/angular/angularfire/blob/master/docs/firestore/collections.md
return { id, ...data };
Why that's referred to as spread syntax! :)
Related
This question already has answers here:
JavaScript object functions and `this` when unbound and returned in expression/parens
(2 answers)
Closed 3 years ago.
I came across this (document.createElement)('a');.
How is it different from document.createElement('a');
No difference.
Please read doc for more.
This question already has answers here:
What do querySelectorAll and getElementsBy* methods return?
(12 answers)
Closed 4 years ago.
My Code is:
document.getElementsByName("username").value = "DUBISTFAKE"
does not work pls help me im new to Js.
Try this.
document.getElementsByName('username')[0].value = 'DUBISTFAKE'
This question already has answers here:
What do multiple arrow functions mean in JavaScript?
(7 answers)
How does the spread syntax in ES6 JS work as a function argument?
(1 answer)
What are these three dots in React doing?
(23 answers)
Closed 5 years ago.
How does this work:
const invert = fn => (...args) => -fn(...args);
Specifically, what is happening with (...args). It behaves as if it is separating the arguments from the function after the first fat arrow, but I suspect there is a better, more specific, explanation. Thanks.
This question already has answers here:
Length of a JavaScript object
(43 answers)
Closed 6 years ago.
I dont see how we can find the length of an object. For arrays i can your array.length but it doesnt work for objects, any suggestions?
Thanks!
Just like that:
Object.keys(objectName).length;
This question already has answers here:
Converting JavaScript object with numeric keys into array
(17 answers)
Closed 6 years ago.
I have this:
How do I turn this into an array?
Object.keys(mounted).map((key) => mounted[key])