diff --git a/README.md b/README.md
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+# Additionell kopia av array
+
+- A-nivå
+- [GitBook](https://coursepress.gitbooks.io/1dv021/content/ovningsuppgifter/del1/additionell-kopia-av-array/)
+
+> __VIKTIGT!__ Innan du börjar arbeta med övningsuppgiften är det viktigt att du följer guiden [Att komma igång med en övningsuppgift](https://coursepress.gitbooks.io/1dv021/content/guider/att-komma-igang-med-en-ovningsuppgift/) för att lägga till övningsuppgiftens repo till ditt repo för övningsuppgifter.
+
+Hämta hem övningsuppgiftens repo och lägg till en .gitignore-fil. Öppna filen `my-array.js` och komplettera funktionen `immutablePushNumber`, som ska returnera en kopia av en array där ett tal lagts till. Funktionen ska vara en så kallad "_pure function_", d.v.s. vara helt utan sidoeffekter.
+
+Funktionen `immutablePushNumber` har två parametrar. Den första parametern är den array som ska kopieras. Den andra parameter är det tal som ska läggas till kopian av arrayen.
+
+Du ska även implementera viss felhantering, innebärande att undantag kastas om fel inträffar. Om första parametern inte är av typen `Array` eller om andra parametern inte är av typen `Number` ska ett undantag av typen `TypeError` kastas.
+
+```js
+const ma = require('./src/my-array');
+let arr = [1, 2, 3];
+let newArray = ma.immutablePushNumber(arr, 4); // newArray must be [1, 2, 3, 4]
+                                               // arr must be unchanged, i.e. arr !== newArray
+```
+
+## Tips
+
+Genom att köra testerna som kommer med övningsuppgiften kan du undersöka om koden du skrivit löst uppgiften (i alla fall enligt testet...).
+
+Funktioner, metoder, etc. som _kan_ komma till användning beroende hur du väljer att lösa uppgiften.
+
+- [if](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else)
+- [Array.isArray](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray)
+- [Array.length](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/length)
+- [Array.slice](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice)
+- [Array.push](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push)
+- [throw](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw)
+- [TypeError](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError)
+
+## Lösningsförslag
+
+- [https://github.com/1dv021/exercise-solution-proposals/tree/master/part-1/additional-array-copy](https://github.com/1dv021/exercise-solution-proposals/tree/master/part-1/additional-array-copy)
diff --git a/app.js b/app.js
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+++ b/app.js
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+/**
+ * The starting  point of the application.
+ *
+ * @author Mats Loock
+ * @version 1.1.0
+ */
+
+'use strict'
+
+const ma = require('./src/my-array.js')
+
+let arr = [1, 2, 3]
+let newArr = ma.immutablePushNumber(arr, 4)
+
+console.log(arr)
+console.log(newArr)
+console.log(arr !== newArr)
diff --git a/package.json b/package.json
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+{
+ "name": "exercise-additional-array-copy",
+   "version": "1.1.0",
+  "main": "app.js",
+  "homepage": "http://coursepress.lnu.se/kurs/grundlaggande-programmering/",
+  "contributors": [
+    {
+      "name": "John Häggerud",
+      "email": "john.haggerud@lnu.se"
+    },
+    {
+      "name": "Johan Leitet",
+      "email": "johan.leitet@lnu.se"
+    },
+    {
+      "name": "Jacob Lindehoff",
+      "email": "jacob.lindehoff@lnu.se"
+    },
+    {
+      "name": "Mats Loock",
+      "email": "mats.loock@lnu.se"
+    }
+  ],
+  "license": "CC-BY-4.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/1dv021/exercise-additional-array-copy.git"
+  },
+  "engines": {
+    "node": ">=0.12.0"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "chai": "^3.5.0",
+    "mocha": "^3.3.0",
+    "snazzy": "^7.0.0",
+    "standard": "*"
+  },
+  "directories": {
+    "test": "test"
+  },
+  "scripts": {
+    "start": "node app.js",
+    "test": "standard | snazzy && mocha --recursive ./test"
+  },
+  "standard": {
+    "globals": [
+      "describe",
+      "context",
+      "before",
+      "beforeEach",
+      "after",
+      "afterEach",
+      "it",
+      "expect"
+    ]
+  }
+}
diff --git a/src/my-array.js b/src/my-array.js
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+++ b/src/my-array.js
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+/**
+ * My-array module.
+ *
+ * @module src/my-array
+ * @author John Häggerud
+ * @author Mats Loock
+ * @version 1.1.0
+ */
+
+'use strict'
+
+/**
+ * Returns a copy of an array where a number has been added to the end of the copy.
+ *
+ * @param {Array} source The array to create a copy of.
+ * @param {Number} number The number to add to the end of the copy of the array.
+ * @throws {TypeError} The source parameter must be an Array; number parameter must be a Number.
+ * @returns {Array} A copy of the source array with an additional number.
+ */
+function immutablePushNumber (source, number) {
+  // TODO: Write your code here.
+}
+
+exports.immutablePushNumber = immutablePushNumber
diff --git a/test/my-array.test.js b/test/my-array.test.js
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+/**
+ * Tests for the my-array module.
+ *
+ * @author John Häggerud
+ * @author Mats Loock
+ * @version 1.1.0
+ */
+
+'use strict'
+
+const ma = require('../src/my-array')
+const expect = require('chai').expect
+
+describe('Test error handling', () => {
+  it('Must throw a TypeError if no parameter is provided.', done => {
+    expect(() => { ma.immutablePushNumber() }).to.throw(TypeError)
+    done()
+  })
+
+  it('Must throw a TypeError if second parameter is not provided.', done => {
+    expect(() => { ma.immutablePushNumber([1]) }).to.throw(TypeError)
+    done()
+  })
+
+  it('Must throw a TypeError if the source parameter is not an Array.', done => {
+    expect(() => { ma.immutablePushNumber('not an array', 1) }).to.throw(TypeError)
+    done()
+  })
+
+  it('Must throw a TypeError if the number parameter is not a Number.', done => {
+    expect(() => { ma.immutablePushNumber([], 'not a number') }).to.throw(TypeError)
+    done()
+  })
+})
+
+describe('Test that the source array is untouched.', () => {
+  it('Must NOT return the same Array object the source parameter refers to.' +
+    '(don\'t forget to make a copy of the source array).', done => {
+    let arr = [1, 2, 3]
+    let res = ma.immutablePushNumber(arr, 4)
+    expect(arr).to.not.eql(res)
+    done()
+  })
+})
+
+describe('Test that the new array contains the provided number', () => {
+  it('Must return a new copy of the source with the the additional number at the end.', done => {
+    let arr = [1, 2, 3]
+    let res = ma.immutablePushNumber(arr, 4)
+    expect(res).to.eql([1, 2, 3, 4])
+    done()
+  })
+
+  it('Must return a new copy of the source, an array, with the the additional number at the end.', done => {
+    let arr = [1]
+    let res = ma.immutablePushNumber(arr, 4)
+    expect(res).to.eql([1, 4])
+    done()
+  })
+
+  it('Must return a new copy of the source, an array, with the the additional number at the end.', done => {
+    let arr = []
+    let res = ma.immutablePushNumber(arr, 4)
+    expect(res).to.eql([4])
+    done()
+  })
+})