TIL that 2^24 items will cause a interesting error

POSTED ON: Mar 07, 2022

TAGS: math javascript errors

Obviously there's not much real use-cases. But that's the fun of finding limitations.

As a map #

const myObject = new Map();

// 50_000_000 is a ES2021 syntax
for (let i = 0; i <= 50_000_000; i++) {
    myObject.set(i,i);
    if(i%100000==0) { console.log(i) }
}

What will happen?

0
100000
200000
…
16400000
16500000
16600000
16700000

Then it will crash after adding approx 16.7M elements and say

Uncaught RangeError: Value undefined out of range for undefined options property undefined

3 undefined?

As a Object #

What if you made it an object?

const myObject = {};

// 50_000_000 is a ES2021 syntax
for (let i = 0; i <= 50_000_000; i++) {
    myObject["myobj_" + i] = i;
    if(i%100000==0) { console.log(i) }
}

The result:

0
100000
200000
…
8000000
8100000
8200000
8300000

Then it freezes!

For the Map: 2^24=16,777,216

For the Object it is around 2^23=8,388,608

Not useful. Not fun trivia!

Via searchvoidstar's post

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