The Generator
object is returned by a generator function and it conforms to both the iterable protocol and the iterator protocol.
The Generator
object is returned by a generator function and it conforms to both the iterable protocol and the iterator protocol.
The Generator
constructor is not available globally. Instances of Generator
must be returned from generator functions:
function* generator() { yield 1; yield 2; yield 3; } const gen = generator(); // "Generator { }" console.log(gen.next().value); // 1 console.log(gen.next().value); // 2 console.log(gen.next().value); // 3
Generator.prototype.next()
Returns a value yielded by the yield
expression.
Generator.prototype.return()
Acts as if a return
statement is inserted in the generator's body at the current suspended position, which finishes the generator and allows the generator to perform any cleanup tasks when combined with a try...finally
block.
Generator.prototype.throw()
Acts as if a throw
statement is inserted in the generator's body at the current suspended position, which informs the generator of an error condition and allows it to handle the error, or perform cleanup and close itself.
With a generator function, values are not evaluated until they are needed. Therefore a generator allows us to define a potentially infinite data structure.
function* infinite() { let index = 0; while (true) { yield index++; } } const generator = infinite(); // "Generator { }" console.log(generator.next().value); // 0 console.log(generator.next().value); // 1 console.log(generator.next().value); // 2 // …
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator