JavaScript Constructors

1. Navigate to this project in your terminal.
2. Run live-server.
3. Open http://localhost:8080 in Chrome.

You should see failing tests.

Create 3 constructor functions by following the comments in constructors.js. Write all of the constructor functions below in constructors.js

After you complete a test:

1. Save constructors.js.
2. Reload http://localhost:8080 in Chrome.
3. Check if the test passes.
4. If it passes, commit your work.

Some comments meant to be nested inside of the constructor function, be sure your code follows the same structure.

Example (Before)

/**
 * An example constructor.
 * @class Represents a constructor function.
 * @param {string} description – The example's description.
 */

  /**
   * Returns the example's description.
   * @return {string} description – This example's description.
   */

Example (After)

/**
 * An example constructor.
 * @class Represents a constructor function.
 * @param {string} description – The example's description.
 */
function Example (description) {
  this.description = description;
}
  /**
   * Returns the example's description.
   * @return {string} description – This example's description.
   */
Example.prototype.getDescription = function() {
  return this.description;
};

---

Spell(name, cost, description)

Creates a generic spell that can be cast.

Parameters

name: string, The name of the spell.

cost: number, The amount needed to cast this spell.

description: string, A short description of the spell.

getDetails()

Returns a string of all of the spell's details. The format doesn't matter, as long as it contains the spell name, cost, and description.

DamageSpell(name, cost, damage, description)

A spell that deals damage. We want to keep this code DRY (Don't Repeat Yourself).

So you should use Spell.call() to assign the spell name, cost, and description.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call

In addition, you will also want to assign DamageSpell.prototype a value so that it inherits from Spell. Make sure to call this OUTSIDE of the function declaration.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/prototype

Parameters

name: string, The name of the spell.

cost: number, The amount needed to cast this spell.

damage: number, The amount of damage this spell deals.

description: string, A short description of the spell.

Spellcaster(name, health, mana)

Now that you've created some spells, let's create Spellcaster objects that can use them!

Parameters

name: string, The spellcaster's name.

health: number, The spellcaster's health points.

mana: number, The spellcaster's mana points, used for casting spells.

inflictDamage(damage)

The spellcaster loses health equal to damage. Health should never be negative. If the spellcaster's health drops to 0, its isAlive property should be set to false.

Parameters

damage: number, Amount of damage to deal to the spellcaster

spendMana(cost)

Reduces the spellcaster's mana by cost. Mana should only be reduced only if there is enough mana to spend.

Parameters

cost: number, The amount of mana to spend.

Returns: boolean, Whether mana was successfully spent.

invoke(spell, target)

Allows the spellcaster to cast spells. The first parameter should either be a Spell or DamageSpell. If it is a DamageSpell, the second parameter should be a Spellcaster. The function should return false if neither of the conditions are not satisfied.

You should use instanceof to check for these conditions.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof

Next check if the spellcaster has enough mana to cast the spell. If it can cast a spell, it should lose mana equal to the spell's cost. If there is not enough mana, return false.

If there is enough mana to cast the spell, return true. In addition, if it is a DamageSpell reduce the target's health by the spell's damage value.

Use functions you've previously created: (inflictDamage, spendMana) to help you with this.

Parameters

spell: Spell | DamageSpell, The spell to be cast.

target: Spellcaster, The spell target to be inflicted.

Returns: boolean, Whether the spell was successfully cast.