The ``++yield++`` keyword is used in a generator function to return an ``++IteratorResult++`` to the caller. It has no other purpose, and if found outside such a function will raise a ``++ReferenceError++`` because it is then treated as an identifier.

== Noncompliant Code Example

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function foo() { 
  for (var i = 0; i < 5; i++) { 
    yield i * 2; 
  } 
}
----

== Compliant Solution

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function * foo() { 
  for (var i = 0; i < 5; i++) { 
    yield i * 2; 
  } 
}
----