JS: Set.prototype.has

By Xah Lee. Date: . Last updated: .

New in ES2015.

set_obj.has(value)

Return true if value is in set. Else, false.

const s = new Set([3,4,5]);

// check existence

console.log ( s.has (5) ); // true
console.log ( s.has (99) ); // false

Reference

ECMAScript 2015 §Keyed Collection#sec-set.prototype.has

Set Topic

  1. JS: the Set Object Tutorial
  2. JS: Set Union, Intersection, Difference
  3. JS: Set Object
  4. JS: Set.prototype
  5. JS: Set.prototype.forEach
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