//// [for-of20.ts] for (let v of new FooIterator) { v; } class Foo { } class FooIterator { next() { return { value: new Foo, done: false }; } [Symbol.iterator]() { return this; } } //// [for-of20.js] for (let v of new FooIterator) { v; } class Foo { } class FooIterator { next() { return { value: new Foo, done: false }; } [Symbol.iterator]() { return this; } }