Check if arrays have same contents
JavaScript, Array · Oct 19, 2020

Checks if two arrays contain the same elements regardless of order.
- Use a
for...of
loop over aSet
created from the values of both arrays. - Use
Array.prototype.filter()
to compare the amount of occurrences of each distinct value in both arrays. - Return
false
if the counts do not match for any element,true
otherwise.
const haveSameContents = (a, b) => {
for (const v of new Set([...a, ...b]))
if (a.filter(e => e === v).length !== b.filter(e => e === v).length)
return false;
return true;
};
haveSameContents([1, 2, 4], [2, 4, 1]); // true
Written by Angelos Chalaris
I'm Angelos Chalaris, a JavaScript software engineer, based in Athens, Greece. The best snippets from my coding adventures are published here to help others learn to code.
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