CODEWITHSUNDEEP
javascript
glotfiovic1v
glotfiovic1v

Reputation: 31

How to group logical operators in JS?

This is simple beginner question - let suposse we have variable status:

var status = 'unknown';

and we want to grab error if:

if (status !== 'good' && status !== 'bad'){// error}

I wanted to shorten it to:

if (status !== 'good' && 'bad'){}

but it's not working? Is this even possible?

Upvotes: 2

Views: 588

Answers (3)

Coder778
Coder778

Reputation: 1

When using the if statement:

  if (status !== 'good' && 'bad'){}

JavaScript is trying to evaluate each side of the && separately. In your example status is 'unknown' so the left side (status !== 'good') will evaluate to true. Then the right side ('bad') will evaluate to true only because a non-empty string is a truthy value (https://developer.mozilla.org/en-US/docs/Glossary/Truthy). So any string (other than '') will evaluate to true and this has nothing to do with the code on the left of the &&.

Upvotes: 0

Benoît
Benoît

Reputation: 360

You could use

if (!['good', 'bad'].includes(status)){}

Upvotes: 2

CertainPerformance
CertainPerformance

Reputation: 371009

To make your code more DRY, you can make an array of conditions and then check to see if the string matches any of those conditions:

if (!['good', 'bad'].includes(status))

There isn't an operator shortcut like you're thinking of, though.

Upvotes: 2

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