폐쇄

function outerFunction() {
  function innerFunction() {
    let text = "I am a closure";
    return text;
  }
  let text = "I am an outer function";
  return text;
}

기능 범위 외부에서 클로저에 액세스 가능하게 만들기

function outerFunction() {
  function innerFunction() {
    let text = "I am a closure";
    return text;
  }
  return innerFunction;
}

// invoking outerFunction to get access to _innerFunction_
console.log(outerFunction()); // returns [Function: innerFunction]
// This shows we have access to the _innerFunction_

console.log(outerFunction()()); // return "I am a closure"

function addition(num1) {
  var addition2 = function (num2) {
    var addition3 = function (num3) {
      return num1 + num2 + num3;
    };
    return addition3;
  };
  return addition2;
}

console.log("3 + 3 + 3 = ", addition(3)(3)(3)); // returns 9
console.log("4 + 5 + 6 = ", addition(4)(5)(6)); // return 15