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danfinlay/map-func-identity.js

Created November 21, 2019 19:40
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Proof that JavaScript maps index functions by identity, not source string.
Raw
map-func-identity.js
const funcString = '() => "foo"';
const funcA = new Function(funcString);
const funcB = new Function(funcString);
const map = new Map();
map.set(funcA, 'a');
map.set(funcB, 'b');
const aVal = map.get(funcA);
console.log(aVal === 'a');
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