Set.prototype.forEach()

Baseline

20157

forEach() Set

function logSetElements(value1, value2, set) {
  console.log(`s[${value1}] = ${value2}`);
}

new Set(["foo", "bar", undefined]).forEach(logSetElements);

// : "s[foo] = foo"
// : "s[bar] = bar"
// : "s[undefined] = undefined"

forEach(callbackFn)
forEach(callbackFn, thisArg)

callback

value
key: value
set

thisArg

callbackFn this

undefined

forEach() Set callback undefined

callback 3

Set

Set 2 Set Map Array forEach()

thisArg forEach() callback this this undefined this callback this

1 forEach() callback forEach()

forEach() callback Set

Set

Set

function logSetElements(value1, value2, set) {
  console.log(`s[${value1}] = ${value2}`);
}

new Set(["foo", "bar", undefined]).forEach(logSetElements);

// Logs:
// "s[foo] = foo"
// "s[bar] = bar"
// "s[undefined] = undefined"


ECMAScript 2027 LanguageSpecification # sec-set.prototype.foreach

Array.prototype.forEach()
Map.prototype.forEach()

MDN

MDN 2026523

GitHub

Set
1. Set()
1. [Symbol.species]
1. size
Object/Function
1. __proto__
2. constructor