My function parameters is not working as expected

Question

Sorry for the stupid question.
So I got this code here:

function stat(x) {
    player.ATK = 0; player.DEF = 0; player.DEX = 0; player.crit = 0; player.HP = 0;
    player.weaponATK = weapon.x.atk;
    player.weaponDEF= weapon.x.def;
    player.weaponDEX = weapon.x.dex;
    player.weaponHP = weapon.x.hp;
    player.weaponCrit = weapon.x.crit;
    player.ATK = player.baseATK + player.weaponATK;
    player.DEF = player.baseDEF + player.weaponDEF;
    player.DEX = player.baseDEX + player.weaponDEX;
    player.HP = player.baseHP + player.weaponHP;
    player.crit = player.baseCrit + player.weaponCrit;
}

And here's the whole var i use:

var player = {
  HP: 0,
  baseHP: 100,
  weaponHP: 0,
  ATK: 0,
  baseATK: 0,
  weaponATK: 0,
  DEF: 0,
  baseDEF: 0,
  weaponDEF: 0,
  DEX: 0,
  baseDEX: 0,
  weaponDEX: 0,
  crit: 0,
  baseCrit: 5,
  weaponCrit: 0,
  level: 1,
  currentEXP: 0,
  expLeft: 10
};
var weapon = {
  hatchet: {
    atk: 2,
    def: -1,
    dex: 0,
    hp: 0,
    crit: 0
  },
  woodenSword: {
    atk: 5,
    dex: 0,
    def: 0,
    hp: 0,
    crit: 0,
  },
  ironSword: {
    atk: 10,
    crit: 5,
    dex: 0,
    def: 0,
    hp: 0
  },
  blade: {
    atk: 25,
    crit: 20,
    dex: 10,
    hp: 0,
    crit: 0,
  },
  mace: {
    atk: 30,
    def: 5,
    dex: -1,
    hp: 0,
    crit: 0,
  },
  battleAxe: {
    atk: 50,
    def: 5,
    dex: 0,
    hp: 0,
    crit: 0,
  },
  broadSword: {
    atk: 100,
    def: 20,
    dex: 0,
    crit: 0,
    hp: 0
  },
  woodenShield: {
    atk: 0,
    def: 10,
    dex: 0,
    hp: 0,
    crit: 0,
  },
  spikeShield: {
    def: 15,
    atk: 5,
    dex: 0,
    crit: 0,
    hp: 0,
  },
  bomb: {
    atk: 0,
    def: 0,
    crit: 0,
    hp: 0,
    dex: -5
  }
};

And if I run stat(hatchet), it suppose to excute the function with x replace with hatchet. But instead, I got a error: "x is not defined". Can someone help me? Thanks for the help.

Possible duplicate of [Dynamically access object property using variable](https://stackoverflow.com/questions/4244896/dynamically-access-object-property-using-variable) — Gerrit0, Jun 03 '17 at 02:52
the parameter is `x` but you are trying to access `weapon.x` — brk, Jun 03 '17 at 02:53
Just simply send `weapon.x` as parameter. Check if it works. — gsthina, Jun 03 '17 at 03:08

Mμ. · Accepted Answer · 2017-06-03T03:14:46.287

I assume that x is a property in weapon object, so you can use the bracket notation to access it from weapon like the following. Finally, when you call stat function, make sure that it is a string. See working code below:

var player = {
  HP: 0,
  baseHP: 100,
  weaponHP: 0,
  ATK: 0,
  baseATK: 0,
  weaponATK: 0,
  DEF: 0,
  baseDEF: 0,
  weaponDEF: 0,
  DEX: 0,
  baseDEX: 0,
  weaponDEX: 0,
  crit: 0,
  baseCrit: 5,
  weaponCrit: 0,
  level: 1,
  currentEXP: 0,
  expLeft: 10
};
var weapon = {
  hatchet: {
    atk: 2,
    def: -1,
    dex: 0,
    hp: 0,
    crit: 0
  },
  woodenSword: {
    atk: 5,
    dex: 0,
    def: 0,
    hp: 0,
    crit: 0,
  },
  ironSword: {
    atk: 10,
    crit: 5,
    dex: 0,
    def: 0,
    hp: 0
  },
  blade: {
    atk: 25,
    crit: 20,
    dex: 10,
    hp: 0,
    crit: 0,
  },
  mace: {
    atk: 30,
    def: 5,
    dex: -1,
    hp: 0,
    crit: 0,
  },
  battleAxe: {
    atk: 50,
    def: 5,
    dex: 0,
    hp: 0,
    crit: 0,
  },
  broadSword: {
    atk: 100,
    def: 20,
    dex: 0,
    crit: 0,
    hp: 0
  },
  woodenShield: {
    atk: 0,
    def: 10,
    dex: 0,
    hp: 0,
    crit: 0,
  },
  spikeShield: {
    def: 15,
    atk: 5,
    dex: 0,
    crit: 0,
    hp: 0,
  },
  bomb: {
    atk: 0,
    def: 0,
    crit: 0,
    hp: 0,
    dex: -5
  }
};

function stat(x) {
    player.ATK = 0; player.DEF = 0; player.DEX = 0; player.crit = 0; player.HP = 0;
    player.weaponATK = weapon[x].atk;
    player.weaponDEF= weapon[x].def;
    player.weaponDEX = weapon[x].dex;
    player.weaponHP = weapon[x].hp;
    player.weaponCrit = weapon[x].crit;
    player.ATK = player.baseATK + player.weaponATK;
    player.DEF = player.baseDEF + player.weaponDEF;
    player.DEX = player.baseDEX + player.weaponDEX;
    player.HP = player.baseHP + player.weaponHP;
    player.crit = player.baseCrit + player.weaponCrit;
}

// make sure x is a string!
stat('hatchet');

console.log(player)

In this case, only bracket notation would work. Dot notation would only work if you are assigning a value to a known property in the object. For example, you want to update the player.baseHP, so you can do `player.baseHP = someVariable`. — Mμ., Jun 03 '17 at 03:23
I try your code, and it says "Cannot read property atk of undefine. — AzDeveloper, Jun 03 '17 at 03:26
The code snippet above works, just try running the code snippet. That error means that weapon object is not defined in your case. — Mμ., Jun 03 '17 at 03:31
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/145756/discussion-between-azdeveloper-and-d-reaper). — AzDeveloper, Jun 03 '17 at 03:33

score 0 · Answer 2 · answered Jun 03 '17 at 02:58

0

It's either what @brk or @D-reaper suggested

player.weaponATK = weapon.x.atk;

and similar need to be either

player.weaponATK = weapon[x].atk;

or just

player.weaponATK = x.atk;

answered Jun 03 '17 at 02:58

m1kael

2,801
1
15
14

score 0 · Answer 3 · answered Jun 03 '17 at 04:31

0

Since x is key passed to access the object property. It has to be used as weapon[x].atk

answered Jun 03 '17 at 04:31

Nemani

778
5
12

My function parameters is not working as expected

3 Answers3