0
134
ViewsUsing optional chaining with array.entries
Just trying to understand optional chaining and unsure if it can be used in the following situation with .entries, that is:
for (const [index, val] of Array.from(myArray)?.entries()) {
if (val.status === 1) {
. . .
. . .
}
}
I basically don't want to proceed if myArray is empty.
·
Juan Pablo Isaza
1 answers
Answer question0
If you look for a short null check, I think your problem is not from Array.from but it's from myArray variable. If myArray is undefined, Array.from(myArray)?.entries() will throw an error
const myArray = undefined
const entries = Array.from(myArray)?.entries() //throw an error
If you want to overcome this, you need to use short circuit evaluation to assign the default value [] whenever myArray is undefined or null
const myArray = undefined
const entries = Array.from(myArray || []).entries() //working!
If myArray is already an array (or possibly an undefined value), you can get rid of Array.from too
const myArray = undefined
const entries = myArray?.entries() || [] //assign a default value for your loop
·
Juan Pablo Isaza
Report
Answer question