Incorporating a requirement into a function to ensure it is executed only under certain circumstances

Question

Incorporating a requirement into a function to ensure it is executed only under certain circumstances

I'm currently developing a text-based game using JavaScript that involves picking up a sword with the help of an in-game function.

var takeSword = function() {
        if (currentRoom.hasSword) {
            $("<p>You picked up a sword.</p>").properDisplay();

        }
        else {
            $("<p>The sword is not here.</p>").properDisplay();
        }
    };

The issue I'm facing is that it's possible to repeatedly pick up the sword while remaining in the same room. How can I modify the function so that once the sword is collected, it cannot be picked up again?

Initially, my approach was to use a variable like var sword = false; and then update it to sword = true; within the function, but this did not prove effective.

This code snippet doesn't cover the entire script; there's an object defined earlier that sets 'hasSword = true;', allowing the sword to be obtained initially but preventing it from being picked up in other areas of the game.

javascript

Answer 1

Answer №1

Maybe something along these lines?

let GameConditions = {
    hasKey: true,
    playerHasKey: false,
    obtainKey: function() {
        if( this.hasKey ) {
            this.hasKey = false;
            this.playerHasKey = true;
            $("<p>You found a key!</p>").displayMessage();
        }
        else {
            $("<p>No key here.</p>").displayMessage();
        }
    }
}

GameConditions.obtainKey();

Answer 2

Maybe something along these lines?

let GameConditions = {
    hasKey: true,
    playerHasKey: false,
    obtainKey: function() {
        if( this.hasKey ) {
            this.hasKey = false;
            this.playerHasKey = true;
            $("<p>You found a key!</p>").displayMessage();
        }
        else {
            $("<p>No key here.</p>").displayMessage();
        }
    }
}

GameConditions.obtainKey();

Answer 3

Answer №2

To improve your code, consider encapsulating your original function within another function that ensures it is only executed once. This wrapper function can be applied to any other parts of your code where you require a similar functionality:

function runOnce(fn, context) { 
    var result;

    return function() { 
        if(fn) {
            result = fn.apply(context || this, arguments);
            fn = null;
        }

        return result;
    };
}

After defining the above function, you can use it like this:

var performTaskOnce = runOnce(performTask);

By using performTaskOnce, you ensure that the specified task runs only once in your script. Alternatively, you can directly modify the original function like so:

performTask = runOnce(performTask);

You may find additional insights on the runOnce function by reading this article.

Answer 4

To improve your code, consider encapsulating your original function within another function that ensures it is only executed once. This wrapper function can be applied to any other parts of your code where you require a similar functionality:

function runOnce(fn, context) { 
    var result;

    return function() { 
        if(fn) {
            result = fn.apply(context || this, arguments);
            fn = null;
        }

        return result;
    };
}

After defining the above function, you can use it like this:

var performTaskOnce = runOnce(performTask);

By using performTaskOnce, you ensure that the specified task runs only once in your script. Alternatively, you can directly modify the original function like so:

performTask = runOnce(performTask);

You may find additional insights on the runOnce function by reading this article.

Answer 5

Answer №3

@Kenney really helped me see things from a different perspective. After some tinkering, I managed to resolve the issue without having to completely overhaul the function:

var takeSword = function() {
        if (currentRoom.hasSword) {
            $("<p>You grabbed the sword.</p>").properDisplay();
            currentRoom.hasSword = false;
        }
        else {
            $("<p>There is no sword here.</p>").properDisplay();
        }
    };

My initial error was assuming "hasSword" was simply a standalone variable. It wasn't until I incorporated the currentRoom object that everything fell into place. I've run tests and even tried it in rooms sans sword, and it appears to be functioning properly.

Answer 6

@Kenney really helped me see things from a different perspective. After some tinkering, I managed to resolve the issue without having to completely overhaul the function:

var takeSword = function() {
        if (currentRoom.hasSword) {
            $("<p>You grabbed the sword.</p>").properDisplay();
            currentRoom.hasSword = false;
        }
        else {
            $("<p>There is no sword here.</p>").properDisplay();
        }
    };

My initial error was assuming "hasSword" was simply a standalone variable. It wasn't until I incorporated the currentRoom object that everything fell into place. I've run tests and even tried it in rooms sans sword, and it appears to be functioning properly.

Incorporating a requirement into a function to ensure it is executed only under certain circumstances

Answer №1

Answer №2

Answer №3

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