Javascript Bind , Call , Apply examples

Javascript Bind , Call , Apply examples

//-----------------------Bind , Call , Apply ------------------------------//

//Example 1
const john = {
  name: "John",
  age: 26,
  job: "Teacher",
  presentation: function(style, timeOfDay) {
    if (style === "formal") {
      console.log(
        "Good " +
          timeOfDay +
          ", Ladies and gentlemen! I'm " +
          this.name +
          " , I'm a " +
          this.job +
          " and I'm " +
          this.age +
          " years old ."
      );
    } else if (style === "friendly") {
      console.log(
        "Hey what's up? That's " +
          this.name +
          " , I'm a " +
          this.job +
          " and I'm " +
          this.age +
          " years old" +
          " Have a nice " +
          timeOfDay +
          " !!"
      );
    }
  }
};

const emily = {
  name: "Emily",
  age: 35,
  job: "Designer"
};

john.presentation("formal", "morning");

//Call
john.presentation.call(emily, "friendly", "morning");

//Apply
john.presentation.apply(emily, ["formal", "morning"]);

console.log("-----------------------------");

//Bind
const emilyFriendly = john.presentation.bind(emily, "friendly");
emilyFriendly("night");

//Example 2
var years = [1990, 1965, 1937, 2005, 1998];

function arrayCalc(arr, fn) {
  let arrRes = [];
  for (var i = 0; i < arr.length; i++) {
    arrRes.push(fn(arr[i]));
  }
  return arrRes;
}

function calculateAge(el) {
  return 2019 - el;
}

function isFullAge(limit, el) {
  return el >= limit;
}

const ages = arrayCalc(years, calculateAge);

console.log("Ages : ", ages);

const fullAgeJapan = isFullAge.bind(this, 20);

const fullAges = arrayCalc(ages, fullAgeJapan);

console.log(fullAges);