Video casino game example

Here is an example of how closures can be used in the context of a video casino game:

function createSlotMachine() {
  let credits = 0;

  return {
    insertCoin: function() {
      credits++;
    },
    play: function() {
      if (credits > 0) {
        // generate random number and determine winnings
        let winnings = Math.floor(Math.random() * 50);
        credits += winnings;
        console.log(`Congratulations, you won ${winnings} credits!`);
      } else {
        console.log('You must insert a coin before you can play.');
      }
    },
    getCredits: function() {
      return credits;
    }
  }
}

let slotMachine = createSlotMachine();
slotMachine.insertCoin();
slotMachine.play(); // may output "Congratulations, you won X credits!"
console.log(slotMachine.getCredits()); // displays the number of credits the player has

In this example, the createSlotMachine function creates a new slot machine object with three methods: insertCoin, play, and getCredits. The insertCoin and play methods are closures that maintain a reference to the credits variable, which is defined in the outer function. This allows the insertCoin and play methods to access and modify the credits variable even after the createSlotMachine function has returned.

The getCredits method returns the value of the credits variable. This method is not a closure, since it does not reference any variables from the outer function.

When the slotMachine object is created, the player can insert coins, play the slot machine, and check their credits using the insertCoin, play, and getCredits methods. The credits variable is private to the slot machine object and cannot be accessed or modified directly from outside the object. This use of a closure helps to encapsulate the state of the slot machine and protect it from tampering.