optional-chaining Questions
1
As far as I know, the null safe operator doesn't work on arrays. Is there another way to achieve the same effect with array chaining?
For example:
$array = [];
if (isset($array['a'])) {
if (isset...
Khanna asked 10/11, 2021 at 21:1
3
I have an async function that returns an optional String.
func traverse(file:URL, for string:String) async throws -> String? {
...
}
I want to run this function and if nil, run it with differen...
Fjord asked 2/8, 2021 at 16:30
4
Solved
So, I am reading optional chaining in JavaScript and a question popped into my head.
Consider the code below:
let person = null
let street = person?.street // returns undefined
My question is that...
Anthem asked 10/4, 2022 at 15:36
3
Solved
i tried to use optional chaining in javascript but my eslint rules causing error .
Error : Unsafe usage of optional chaining. If it short-circuits with 'undefined' the evaluation will throw TypeErr...
Wattmeter asked 7/3, 2023 at 7:27
3
Solved
When deserializing deeply nested structures (e.g. from JSON), it's not uncommon to have to traverse multiple Option types.
For example:
let foo = Foo {
x: Some(Bar {
y: Some(Baz {
z: Some(42),
...
Round asked 4/5, 2022 at 17:2
3
Solved
Is there any reason to use if to check if method exists, before calling await
if (someObject.save){
await someObject.save();
}
rather than using nullish coallescence diectly with await
await som...
Sclerophyll asked 7/11, 2022 at 17:4
8
Solved
Is there an easy way to natively determine if a deep property exists within an object in JavaScript? For example, I need to access a property like this:
var myVal = appData.foo.bar.setting;
But ...
Lockman asked 3/10, 2011 at 15:1
1
I have a data structure that is deeply nested and I want to be able to reference an inner type in it, but that type doesn't have its own name/definition. For example:
MyQuery['system']['errors']['l...
Pandemic asked 25/11, 2020 at 16:1
4
Solved
Project setup:
Vuejs 3
Webpack 4
Babel
TS
We created the project using vue-cli and add the dependency to the library.
We then imported a project (Vue Currency Input v2.0.0) that uses optional ...
Luminosity asked 17/6, 2021 at 9:33
1
Optional chaining isn't working on my Vue.js (v2) project on Node 14.17.
const adventurer = {
name: 'Alice',
cat: {
name: 'Dinah'
}
};
const dogName = adventurer.dog?.name;
console.log(dogName...
Merideth asked 17/9, 2021 at 9:17
5
Solved
I'm trying to use optional chaining with an array instead of an object but not sure how to do that:
Here's what I'm trying to do myArray.filter(x => x.testKey === myTestKey)?[0].
Also trying sim...
Bunn asked 7/1, 2020 at 7:5
1
Solved
Coming from a background in C# the null-conditional operator allows you to call a function avoiding a possible null-reference exception like so:
Func<int> someFunc = null;
int? someInteger = ...
Marten asked 23/10, 2021 at 19:36
1
In the vue/vuetify project, while trying to get optional chaining (https://babeljs.io/docs/en/babel-plugin-proposal-optional-chaining) to work, I always encounter an error:
./src/App.vue?vue&t...
Genoese asked 23/12, 2020 at 16:9
1
Solved
console.log("#1", "a12312a".match(/^\d+/)?.[0].length);
console.log("#2", ("a12312a".match(/^\d+/)?.[0]).length);
I was writing some code and stumbled upon something I don’t understand. ...
Psychrometer asked 22/4, 2021 at 7:9
7
Solved
My problem is a general one, how to chain a series of attribute lookups when one of the intermediate ones might return None, but since I ran into this problem trying to use Beautiful Soup, I'm goin...
Kellum asked 7/3, 2013 at 19:55
2
Solved
Using optional chaining with function calls causes the expression to automatically return undefined instead of throwing an exception if the method isn't found.
Note: The code is using spread synt...
Indispensable asked 13/3, 2021 at 2:46
3
Solved
Scenario:
We're using webpack 4 to create a bundle from our Javascript sources.
We're not using Babel because we're authoring only for a single platform (latest Chrome), and we're only using fe...
Philosophy asked 29/1, 2020 at 17:16
1
Solved
I have a response which I am accessing: data?.currentOrganization?.onboardingSteps?. As you can guess, data, currentOrganization, and onboardingSteps might all be null. I want to assign a variable ...
Mastersinger asked 2/2, 2021 at 21:31
2
Solved
TypeScript 3.7 now supports the optional chaining operator. Hence, you can write code such as:
const value = a?.b?.c;
I.e., you can use this operator to access properties of an object, where the o...
Aquanaut asked 9/11, 2019 at 15:42
1
Just updated to Angular 10 from 9.0
Every use of Optional Chaining (https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#optional-chaining) in my code now results in its o...
Entirety asked 24/7, 2020 at 0:44
1
Vs code > OUTPUT > Prettier
2/23/2020, 12:10:36 PM:
-----------------------
Expression expected. (/Users/yanivper/dev/test/test.ts:2:23)
1 | function test(obj) {
2 | return obj.a?.b;
^
In a new...
Palaeozoic asked 23/2, 2020 at 10:19
7
Solved
I've been programming a lot in Swift recently. Today I did some work in JavaScipt when question popped up to me:
Is there something similar to optional chaining in JavaScript? A way to preve...
Midyear asked 3/10, 2014 at 17:39
3
Solved
Currently I am using below code for destructuring:
const myObj1 = {name: 'Abc'}
const {name} = myObj1
console.log(name)
const myObj2 = null
const {name2} = myObj2 // this will give error
...
Catalyze asked 4/7, 2020 at 9:41
1
Solved
I had an if statement in code which checks whether an object is defined and then check for equality for one of its properties. My if statement was like:
if(obj && obj.a !== x) { // do somet...
Sumba asked 26/6, 2020 at 22:13
2
I have a TypeScript interface with some optional fields and a variable of that type:
interface Foo {
config?: {
longFieldName?: string;
}
}
declare let f: Foo;
I'd like to put longFieldName ...
Shanitashank asked 14/11, 2019 at 21:6
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