Hint
Values passed to next(val) become the result of the yield expression — two-way communication. The FIRST next() can't pass a value (nothing waiting for it).
function* calculator() {
const x = yield 'Enter x:';
const y = yield 'Enter y:';
return x + y;
}
const calc = calculator();
console.log(calc.next().value);
console.log(calc.next(10).value);
console.log(calc.next(5).value);Enter x: Enter y: 15
Explanation: First next(): runs to first yield, returns "Enter x:". next(10): resumes — 10 is the result of that first yield expression (x=10) — runs to second yield, returns "Enter y:". next(5): 5 becomes y, returns x+y = 15.
Key Insight: Values passed to next(val) become the result of the yield expression — two-way communication. The FIRST next() can't pass a value (nothing waiting for it).