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JavaScript

Posted by John Weland
John Weland
42,478 Points

JavaScript extends

So I got bored while following along the OO JavaScript course and I decided to make a little console based player vs monster game.

I am noticing that my objects Monster and Player have near identical prototypes for attack and success (<--- success is a simple bool for detecting if a attack could be blocked or if the monster can counter).

"use strict";

function Player (name) {
    this.name = name;
    this.health = 10;
    this.luck = 5;
}
Player.prototype.attack = function(target) {
    clear();
    if (this.health > 0) {
        if (target.health > 0) {
            console.log(this.name + ' attacks ' + target.name);
            if (target.success(this)) {
                console.log(target.name + ' dodged the attack!');
            } else {
                target.health--;
                console.log(target.name + '\'s health is ' + target.health);
            }
            if (target.success(this)) {
                console.log(target.name + ' counter attacks!');
                target.attack(this);
            }
            console.log('\n \n');
            console.log('SIMULATED NEW TURN');
            target.attack(this);
        } else {
            console.log(target.name + ' is defeated!');
        }
    } else {
        console.log(this.name + ' has fallen!');
    }
}

Player.prototype.success = function(target) {
    this.attackerBonus = this.luck;
    this.defenderBonus = target.luck;
    var odds = Math.ceil(Math.random() * 100) + (this.attackerBonus - this.defenderBonus);
    if (odds > 70) {
        return true;
    }
    return false;
}

function Enemy (name, type) {
    this.name = name;
    this.health = 10;
    this.type = type;
    this.luck = 4;
}

Enemy.prototype.attack = function(target) {
    if (this.health > 0) {
        if (target.health > 0) {
            console.log(this.name + ' bites'); 
            if (target.success(this)) {         
                console.log(target.name + ' dodged the attack!');
            } else {
                target.health--;
                console.log(target.name + '\'s health is ' + target.health);
            }

        } else {
            console.log(target.name + ' has fallen!');
        }    
    } else {
        console.log(this.name + ' has been defeated!');
    }    
}
Enemy.prototype.success = function(target) {
    this.attackerBonus = this.luck;
    this.defenderBonus = target.luck;
    var odds = Math.ceil(Math.random() * 100) + (this.attackerBonus - this.defenderBonus);
    if (odds > 70) {
        return true;
    }
    return false;
}

var Fenrir = new Enemy('Fenrir', 'wolf');
var Thor = new Player('Thor');

I was thinking of creating another object called Action that has the shared prototypes and the Player and Monster can extend Action... but I can't figure it out.

BTW copy the code and past it in the console and then try Thor.attack(Fenrir); to play

John Weland
John Weland
42,478 Points

UPDATED CODE ::

here is my updated code, working although I'm not happy with the console logs because I want to output different things for the object type ie player.attack (target) should output => "player attacks", enemy.attack(target) should maybe output => "bites". 

"use strict";

function Character (name) {
    this.name = name;
}

Character.prototype.attack = function(target) {
    clear();
    if (!this.health > 0) {
        console.log(this.name + ' has fallen!');
    } else {
        if (!target.health > 0) {
            console.log(target.name + ' is dead.');
        } else {
            console.log(this.name + ' attacks.');
            if (target.success(this)) {
                console.log(target.name + ' dodged the attack!')
            } else {
                target.health--;
                console.log(target.name + '\'s health is ' + target.health);
            }

            if (target.success(this)) {
                console.log(target.name + ' counters...');
                target.attack(this);
            } 
        }
    } 
}
Character.prototype.success = function(target) {
    this.attackerBonus = this.luck;
    this.defenderBonus = target.luck;
    var odds = Math.ceil(Math.random() * 100) + (this.attackerBonus - this.defenderBonus);
    if (odds > 70) {
        return true;
    }
    return false;
}

function Player (name) {
    Character.call(this, name);
    this.health = 10;
    this.luck = 5;
}
Player.prototype = Object.create(Character.prototype);

function Enemy (name, type) {
    Character.call(this, name);
    this.health = 10;
    this.type = type;
    this.luck = 4;
}
Enemy.prototype = Object.create(Character.prototype);

var fenrir = new Enemy('Fenrir', 'wolf');
var thor = new Player('Thor');

1 Answer

Steven Parker
Steven Parker
229,670 Points
Steven Parker
Steven Parker
229,670 Points

Since your characters already have a type, you could do this:

            console.log(this.name + (this.type=='wolf' ? ' bites.' : ' attacks.'));

Or, you could add an attacktype property to each character, set to 'attack' for players and 'bite' for fenrir, and do this:

            console.log(this.name + ' ' + this.attacktype + 's.');

Oh, and good job overall! :+1:

:information_source: Bonus tip:

// you can replace all this:
    if (odds > 70) {
        return true;
    }
    return false;

// with this:
    return odds > 70;
John Weland
John Weland
42,478 Points

Thanks, I actually went with the attacktype before reading this. (good to know I'm on the same page as others)

I had types because I thought about having types of enemies and even ranks of types so a House Cat vs Lion they are both feline but the lion might be substantially more powerful. Also I could later add things like ground attacks are useless against flying type enemies. for example.

Of course this would be the very basics of only a part of this like battle mechanics in a larger game engine.

While this started out as a way for me to better understand objects, I am thinking of adding promises so I can add cooldowns for attacks etc. IDK.... I think I want to build a little game maybe make it an open project.

John Weland
John Weland
42,478 Points

https://github.com/gamesyndicate/engine