array-iterators.md

Iterators Only!

You have some pure functions to write, your functions should take parameters and return a result!

Method	Description
.map()	creates a new array by performing a callback function on each array element
.filter()	creates a new array with array elements that pass a certain condition
.reduce()	takes all of the elements in an array and "reduces" them to a single value

Time to practice the different Array iterators!

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1. Practice Syntax

Capital names 🏰

Write a function that:

• Takes an array of names as a parameter.
• It needs return a new array with each of the first letters of the names capitalized

// EXAMPLE INPUT -> ["charlie", "rob"];
// EXPECTED OUTPUT -> ["Charlie", "Rob"]

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Remove vowels 📓

Write a function that:

• Takes an array of letters as a parameter.
• It needs return a new array with only consonants, the vowels need to be removed.

// EXAMPLE INPUT -> ["c", "r", "a"];
// EXPECTED OUTPUT -> ["c", "r"]

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Mean coaches 💭

Write a function that:

• Takes an array of numbers as a parameter
• It needs to return the mean average
  • Total the numbers and divide by the amount of numbers in the array

// EXAMPLE INPUT -> [25, 50, 175, 50];
// EXPECTED OUTPUT -> 75

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2. Practice Problem Solving

Spot the difference 👀

Write a function that:

• Takes an array of words
• Returns a new array of words
• Figure out the difference with the examples below and use an array iterator method to implement it.

// EXAMPLE INPUT -> ["spray", "limit", "disco", "exuberant", "destruction", "present"];
// EXPECTED OUTPUT -> ["exuberant", "destruction", "present"]

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Disco Shoes 👞

Write a function that:

• Takes an array of words
• Returns a new array of words
• Figure out the difference with the examples below and use an array iterator method to implement it.

// EXAMPLE INPUT -> ["please camel", "join casing", "these disco", "with shoes"];
// EXPECTED OUTPUT -> ["pleaseCamel", "joinCasing", "theseDisco", "withShoes"]

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Scrabble 🥚

Write a function that:

• Takes an array of scrabble tile objects
• Returns a score
• Figure out the difference with the examples below and use an array iterator method to implement it.

// EXAMPLE INPUT -> [{ letter: "a", value: 1}, { letter: "k", value: 5}, { letter: "c", value: 3}];
// EXPECTED OUTPUT -> 9

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3. Array's and Objects

Mi to Km 🌐

Write a function that:

• Takes an array of mile values as a parameter.
• It needs to convert them from miles to kilometers
• It needs to total them
• It needs to return an object with two keys
  • totalKM : The total of the mile values in km
  • convertedKM : The array of converted mile values

// EXAMPLE INPUT -> = [10, 5];
// EXPECTED OUTPUT -> { convertedKM:[16.0934, 8.04672], totalKM: 24.14012 }

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Filter food 🍔

Write a function that:

• Takes an array of food objects and a food type either junk or healthy
• It needs to return a new array of objects filtered on whether they are the given food type.

// EXAMPLE INPUT -> [
//  { img: "🍕", name: "pizza", foodType: "junk" },
//  { img: "🍔", name: "burger", foodType: "junk" },
//  { img: "🍟", name: "fries", foodType: "junk" },
//  { img: "🌭", name: "hot dog", foodType: "junk" },
//  { img: "🥗", name: "salad", foodType: "healthy" },
//  { img: "🥙", name: "pita", foodType: "healthy" },
//  { img: "🥪", name: "sandwich", foodType: "healthy" },
//  { img: "🌯", name: "burrito", foodType: "healthy" },
//  { img: "🥣", name: "soup", foodType: "healthy" },
// ];

// EXPECTED OUTPUT -> JUNK -> [
//   { img: "🍕", name: "pizza", foodType: "junk" },
//   { img: "🍔", name: "burger", foodType: "junk" },
//   { img: "🍟", name: "fries", foodType: "junk" },
//   { img: "🌭", name: "hot dog", foodType: "junk" },
// ]

// EXPECTED OUTPUT -> HEALTHY -> [
//   { img: "🥗", name: "salad", foodType: "healthy" },
//   { img: "🥙", name: "pita", foodType: "healthy" },
//   { img: "🥪", name: "sandwich", foodType: "healthy" },
//   { img: "🌯", name: "burrito", foodType: "healthy" },
//   { img: "🥣", name: "soup", foodType: "healthy" },
// ]

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We can be Heros 🌎

Write a function that:

• Takes an array of hero objects
• It needs to return a new array of new hero objects where:
  • The name key is changed to hero
  • It should have a new key added called id, the value should be based on its index.
  • It should have a new key added called power, the value should be a random number between 1 - 10.

// EXAMPLE INPUT -> [
//  { name: "Spider-Man" },
//  { name: "Thor" },
//  { name: "Black Panther" },
//  { name: "Captain Marvel" },
//  { name: "Silver Surfer" },
// ];

// EXPECTED OUTPUT -> [
//   { id: 0, hero: "Spider-Man", power: 1 },
//   { id: 1, hero: "Thor", power: 9 },
//   { id: 2, hero: "Black Panther", power: 10 },
//   { id: 3, hero: "Captain Marvel", power: 8 },
//   { id: 4, hero: "Silver Surfer", power: 2 },
// ];

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