prototype.js

// 1. CONSTRUCTOR FUNCTION
// Defines properties unique to each instance
function Robot(name, type) {
    this.name = name;
    this.type = type;
    this.energy = 100;
}

// 2. PROTOTYPE METHODS
// Shared methods defined once to save memory
Robot.prototype.introduce = function() {
    return `ID: ${this.name} | Unit: ${this.type}`;
};

Robot.prototype.work = function() {
    if (this.energy > 0) {
        this.energy -= 10;
        return `${this.name} is working... Energy: ${this.energy}%`;
    }
    return `${this.name} is out of battery!`;
};

// 3. CREATING INSTANCES
const alpha = new Robot("Alpha-1", "Miner");
const beta = new Robot("Beta-7", "Builder");

// 4. USAGE
console.log(alpha.introduce()); 
console.log(beta.introduce());  

console.log(alpha.work());
console.log(alpha.work());

// Checking memory efficiency
console.log(alpha.introduce === beta.introduce); // true