Return null instead of error for object of null

Question

var myVar = null;
console.log(myVar.test)

The above code returns this error: Uncaught TypeError: Cannot read property 'test' of null. How can I just get it to return null without any errors?

I could use a try/catch or an if statement to first check myVar, but is there a simpler way?

it is a proposal, that doesnt work yet ;) its a concept present in a lot of modern languages and is called "null propagator" — Marian Theisen, Aug 13 '19 at 17:18
`console.log(myVar && myVar.test);` will log `myVar` if it is falsey (including `null`), but will log `myVar.test` if `myVar` is truthy (including any object, except `document.all` in a browser). — Paul, Aug 13 '19 at 17:19
that said: simplest solution is `myVar && myVar.test`. if you have deeper digging with possible nulls to do, use lodash's `get` or similar functions — Marian Theisen, Aug 13 '19 at 17:19
Also note that in the future you can use [optional chaining](https://github.com/tc39/proposal-optional-chaining) (currently stage 3). — 3limin4t0r, Aug 13 '19 at 17:28

score 1 · Accepted Answer · answered Aug 13 '19 at 17:18

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console.log(myvar ? myvar.test : 'myvar is null')

You can use an inline ternary operation to check if it's null.

If it's not null, test is printed. If it is, "myvar is null" is printed. This has the advantage over myvar && myvar.test of allowing you to determine the output if myvar is null.

answered Aug 13 '19 at 17:18

Michael Bianconi

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Thanks! Just what I'm looking for. – nachshon f Aug 13 '19 at 17:21
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@3limin4t0r That also wouldn't work if `myVar.test === 0` or any other falsey value (at least, it would evaluate to "myvar is null" for `myVar = {test:0}`). – Paul Aug 13 '19 at 17:27
I can confirm that ```myvar={test:0};``` and ```console.log(myvar && myvar.test || 'myvar is null')``` prints ```'myvar is null'```. – Michael Bianconi Aug 13 '19 at 17:35

Return null instead of error for object of null

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