The argument 10 gets passed to the anonymous inner function, bypassing the outer function. What is the principle here?
function aFunc() {
let firstNum = 2;
return (secondNum) => secondNum * firstNum;
}
let aVar = aFunc();
console.log(aVar(10));
Because aVar is (secondNum) => secondNum * firstNum where firstNum and the closure has firstNum = 2.
function aFunc() {
let firstNum = 2;
return (secondNum) => secondNum * firstNum;
}
let aVar = aFunc();
Calling aFunc() runs the function which creates a closure around firstNum and returning the arrow function (secondNum) => secondNum * firstNum.
The subsequent call to aVar(10) calls this arrow function and the result of adding firstNum (2) and secondNum (10) is calculated and returned.
console.log(aVar(10));