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bob.ts
bob.ts

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Opinionated use of JavaScript Switch-Case

#javascript #webdev #beginners #codenewbie

The Idea

Having just read the Basics of switch cases and defaults, I am reminded of a group code-review I did years ago where I included a switch case-statement in my front end code.

The Code

I would also like to point out that one of our back-end developers (.NET) tried the same pattern and found that it worked, much to his surprise.

This is not the code, but exemplifies what I did ...

const bob = true; const tom = false; const time = false; switch (true) { case (bob === true): case (tom === true): console.log('person'); break; case (time=== true): console.log('time'); break; case default: console.log('other'); break; }
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Granted with this code, we don't know which is true (bob or tom) without additional testing, but ...

Conclusion

... using the switch (true) like this gives us a great visible pattern that is not dependent on any single variable.

I'm not saying this is for everyone, but I personally think this is a very clear pattern.

Top comments (3)

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sirseanofloxley profile image
Sean Allin Newell •

Wat. I am so intrigued

const someFlag = true; const name = 'bob'; // or tom switch (name) { case 'bob': return someFlag ? 20 : 10; case 'tom': return 5; default: return -1; }
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This seems clearer to me, but i can see the flexibility of your way.

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rfornal profile image
bob.ts •

I agree that yours might be clearer with a smaller example, but when using something with dozens of variables, it's clear and the flexibility is really nice.

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jkimexploring profile image
JkImExploring •

This is really cool! I know I've seen this type of pattern with the empty case before but I haven't explored using it too much yet.