---
id: 5d71bdca848f6914ab89897e
title: Part 81
challengeType: 0
---

## Description
<section id='description'>

Use the `shift()` method on the `inventory` array to remove the first element and return that removed element. Set `currentWeapon` to equal returned element. 

Here is an example:

```js
let arr = ["one", "two", "three"];
let firstElement = arr.shift();
// arr now equals ["two", "three"] and firstElement now equals "one"
```

</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: See description above for instructions.
    testString: assert(code.match(/if\s*\(\s*inventory\.length\s*\>\s*1\s*\)\s*\{\s*(.\s*)*let\s*currentWeapon\s*\=\s*inventory\.shift\(\s*\)\;?/));

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='html-seed'>

```html
<script>
let xp = 0;
let health = 100;
let gold = 50;
let currentWeapon = 0;
let fighting;
let monsterHealth;
let inventory = ["stick"];

const button1 = document.querySelector('#button1');
const button2 = document.querySelector("#button2");
const button3 = document.querySelector("#button3");
const text = document.querySelector("#text");
const xpText = document.querySelector("#xpText");
const healthText = document.querySelector("#healthText");
const goldText = document.querySelector("#goldText");
const monsterStats = document.querySelector("#monsterStats");
const monsterNameText = document.querySelector("#monsterName");
const monsterHealthText = document.querySelector("#monsterHealth");

const weapons = [
  {
    name: "stick",
    power: 5
  },
  {
    name: "dagger",
    power: 30
  },
  {
    name: "claw hammer",
    power: 50
  },
  {
    name: "sword",
    power: 100
  }
];

const locations = [
  {
    name: "town square",
    "button text": ["Go to store", "Go to cave", "Fight dragon"],
    "button functions": [goStore, goCave, fightDragon],
    text: "You are in the town square. You see a sign that says \"Store.\""
  },
  {
    name: "store",
    "button text": ["Buy 10 health (10 gold)", "Buy weapon (30 gold)", "Go to town square"],
    "button functions": [buyHealth, buyWeapon, goTown],
    text: "You enter the store."
  },
  {
    name: "cave",
    "button text": ["Fight slime", "Fight fanged beast", "Go to town square"],
    "button functions": [fightSlime, fightBeast, goTown],
    text: "You enter the cave. You see some monsters."
  }
];

// initialize buttons
button1.onclick = goStore;
button2.onclick = goCave;
button3.onclick = fightDragon;

function update(location) {  
  button1.innerText = location["button text"][0];
  button2.innerText = location["button text"][1];
  button3.innerText = location["button text"][2];
  button1.onclick = location["button functions"][0];
  button2.onclick = location["button functions"][1];
  button3.onclick = location["button functions"][2];
  text.innerText = location.text;
}

function goTown() {
  update(locations[0]);
}

function goStore() {
  update(locations[1]);
}

function goCave() {
  update(locations[2]);
}

function fightDragon() {
  console.log("Fighting dragon.");
}

function buyHealth() {
  if (gold >= 10) {
    gold -= 10;
    health += 10;
    goldText.innerText = gold;
    healthText.innerText = health;
  } else {
    text.innerText = "You do not have enough gold to buy health.";
  }
}

function buyWeapon() {
  if (currentWeapon < weapons.length - 1) {
    if (gold >= 30) {
    gold -= 30;
    currentWeapon++;
    goldText.innerText = gold;
    let newWeapon = weapons[currentWeapon].name;
    text.innerText = "You now have a " + newWeapon + ".";
    inventory.push(newWeapon);
    text.innerText += " In your inventory you have: " + inventory;
    } else {
    text.innerText = "You do not have enough gold to buy a weapon.";
    }
  } else {
    text.innerText = "You already have the most powerful weapon!";
    button2.innerText = "Sell weapon for 15 gold";
    button2.onclick = sellWeapon;
  }
}

function sellWeapon() {
  if (inventory.length > 1) {
    gold += 15;
    goldText.innerText = gold;
    let currentWeapon;
  }
}

function fightSlime() {
}

function fightBeast() {
}

</script>
```

</div>


### Before Test
<div id='html-setup'>

```html
<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
  <title>RPG - Dragon Repeller</title>
  <style>
    body {
      background-color: darkblue;
    }
    #text {
      background-color: black;
      color: white;
      padding: 10px;
    }
    #game {
      max-width: 500px;
      max-height: 400px;
      background-color: lightgray;
      color: white;
      margin: 0 auto;
      padding: 10px;
    }
    #controls {
      border: 1px black solid;
      padding: 5px;
    }
    #stats {
      border: 1px black solid;
      color: black;
      padding: 5px;
    }
    #monsterStats {
      display: none;
      border: 1px black solid;
      color: white;
      padding: 5px;
      background-color: red;
    }
    .stat {
      padding-right: 10px;
    }
  </style>
</head>
<body>
<div id="game">
  <div id="stats">
    <span class="stat">XP: <strong><span id="xpText">0</span></strong></span>
    <span class="stat">Health: <strong><span id="healthText">100</span></strong></span>
    <span class="stat">Gold: <strong><span id="goldText">50</span></strong></span>
  </div>
  <div id="controls">
    <button id="button1">Go to store</button>
    <button id="button2">Go to cave</button>
    <button id="button3">Fight dragon</button>
  </div>
  <div id="monsterStats">
    <span class="stat">Monster Name: <strong><span id="monsterName"></span></strong></span>
    <span class="stat">Health: <strong><span id="monsterHealth"></span></strong></span>
  </div>
  <div id="text">Welcome to Dragon Repeller. You must defeat the dragon that is preventing people from leaving the town. You are in the town square. Where do you want to go? Use the buttons above.</div>
</div>
```

</div>


### After Test
<div id='html-teardown'>

```html
</body>
</html>
```

</div>


</section>

## Solution
<section id='solution'>


```html
<script>
let xp = 0;
let health = 100;
let gold = 50;
let currentWeapon = 0;
let fighting;
let monsterHealth;
let inventory = ["stick"];

const button1 = document.querySelector('#button1');
const button2 = document.querySelector("#button2");
const button3 = document.querySelector("#button3");
const text = document.querySelector("#text");
const xpText = document.querySelector("#xpText");
const healthText = document.querySelector("#healthText");
const goldText = document.querySelector("#goldText");
const monsterStats = document.querySelector("#monsterStats");
const monsterNameText = document.querySelector("#monsterName");
const monsterHealthText = document.querySelector("#monsterHealth");

const weapons = [
  {
    name: "stick",
    power: 5
  },
  {
    name: "dagger",
    power: 30
  },
  {
    name: "claw hammer",
    power: 50
  },
  {
    name: "sword",
    power: 100
  }
];

const locations = [
  {
    name: "town square",
    "button text": ["Go to store", "Go to cave", "Fight dragon"],
    "button functions": [goStore, goCave, fightDragon],
    text: "You are in the town square. You see a sign that says \"Store.\""
  },
  {
    name: "store",
    "button text": ["Buy 10 health (10 gold)", "Buy weapon (30 gold)", "Go to town square"],
    "button functions": [buyHealth, buyWeapon, goTown],
    text: "You enter the store."
  },
    {
    name: "cave",
    "button text": ["Fight slime", "Fight fanged beast", "Go to town square"],
    "button functions": [fightSlime, fightBeast, goTown],
    text: "You enter the cave. You see some monsters."
  }
];

// initialize buttons
button1.onclick = goStore;
button2.onclick = goCave;
button3.onclick = fightDragon;

function update(location) {  
  button1.innerText = location["button text"][0];
  button2.innerText = location["button text"][1];
  button3.innerText = location["button text"][2];
  button1.onclick = location["button functions"][0];
  button2.onclick = location["button functions"][1];
  button3.onclick = location["button functions"][2];
  text.innerText = location.text;
}

function goTown() {
  update(locations[0]);
}

function goStore() {
  update(locations[1]);
}

function goCave() {
  update(locations[2]);
}

function fightDragon() {
  console.log("Fighting dragon.");
}

function buyHealth() {
  if (gold >= 10) {
    gold -= 10;
    health += 10;
    goldText.innerText = gold;
    healthText.innerText = health;
  } else {
    text.innerText = "You do not have enough gold to buy health.";
  }
}

function buyWeapon() {
  if (currentWeapon < weapons.length - 1) {
    if (gold >= 30) {
    gold -= 30;
    currentWeapon++;
    goldText.innerText = gold;
    let newWeapon = weapons[currentWeapon].name;
    text.innerText = "You now have a " + newWeapon + ".";
    inventory.push(newWeapon);
    text.innerText += " In your inventory you have: " + inventory;
    } else {
    text.innerText = "You do not have enough gold to buy a weapon.";
    }
  } else {
    text.innerText = "You already have the most powerful weapon!";
    button2.innerText = "Sell weapon for 15 gold";
    button2.onclick = sellWeapon;
  }
}

function sellWeapon() {
  if (inventory.length > 1) {
    gold += 15;
    goldText.innerText = gold;
    let currentWeapon = inventory.shift();
  }
}

function fightSlime() {
}

function fightBeast() {
}
</script>
```

</section>