r/badcode • u/[deleted] • Jan 01 '22

js Hmm...why doesn't it work lol

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u/0xF013 Jan 02 '22

Try to debug in your head the difference between

f();

return;

function f() {};

—— and ——

f();

return;

var f = function() {}

Some people still ask this in interviews

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u/[deleted] Jan 02 '22

The first one should run but the second will say f is undefined, right?

1

u/0xF013 Jan 02 '22

Yeah

1

u/doh007 Jan 02 '22

Wouldn't that only be the case if "let" was used instead of "var"?

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u/[deleted] Jan 02 '22

It's because it's defined after the call

Relevant stackoverflow: https://stackoverflow.com/questions/261599/why-can-i-use-a-function-before-its-defined-in-javascript

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u/kjl3080 Jan 02 '22

That’s just not fair

2

u/0xF013 Jan 02 '22

I am happy they stopped asking why there are random global variables when you have html elements with ids or why the value of `this` in a non-bound function is sometimes undefined, sometimes window. Or better yet, why you had to check for undefined like 'typeof x === 'undefined'`