thisInConstructorFunction.js

function Person(firstName, lastName) {
  this.first_name = firstName
  this.last_name = lastName

  this.displayName = function () {
    console.log(`Name: ${this.first_name} ${this.last_name}`) // Name: Akash Rajvanshi
  }
}

let person = new Person("Akash", "Rajvanshi")
person.displayName()