sf-wdi-35/js-data-types-training

[javascript, control flow, loop, conditional, object, array]

Training: JavaScript Data Types

Use the JavaScript console in your browser to solve the challenges. Press command + option + J to open the console in Chrome. Feel free to also record your responses in a file, but make sure you test them in the console!

Strings

1. Store your first name in a variable.
2. Concatenate your first name with your last name, and store the result in another variable.
3. Use the String split method to turn your string variable from challenge #2 into an array.

Arrays

1. An array called foods holds the names of my top 20 favorite foods, starting with the best food. How can you find my fifth favorite food?

answer

```js foods[4] ```

2. Starting from the existing friends variable below, change the element that is currently "Elizabeth" to "Liz".

var friends = [
  "Moe",
  "Jane",
  "Emma",
  "Elizabeth",
  "Abanov",
  "Lycia"
];

answer

```js friends[3] = "Liz"; ```

3. Using array methods, add your name to the end of the friends array, and add another name to beginning.

hint

Look up array methods `push` and `unshift`.

answer

```js friends.push("Me!"); friends.unshift("Someone else!"); ```

4. We have two lists of friends below. Use array methods to combine them into one alphabetically-sorted list.

var myFriends = [
  "Rickon",
  "Meera",
  "Hodor",
  "Jojen",
  "Osha",
  "Rickard",
  "Maester"
];

var yourFriends = [
  "Bilbo",
  "Boromir",
  "Elrond",
  "Faramir",
  "Frodo",
  "Gandalf",
  "Legolas",
  "Pippin"
];

hint

Look up array methods `concat` and `sort`.

answer

```js var allFriends = myFriends.concat(yourFriends); allFriends.sort(); ```

5. This array contains 2 arrays, of different groups of friends. But everyone became friends! Merge these two arrays into a single array using array methods.

var friends = [
  [
    "George",
    "John",
    "Ringo",
    "Paul"
  ], [
    "Brian",
    "Mick",
    "Keith",
    "Ian",
    "Bill",
    "Charlie"
  ]
]

answer

```js friends[0].concat(friends[1]); ```

Strings & Arrays

1. We have an array of the cardinal directions. In one line, get the first letter of the word "north" from this array.

var directions = [
"north",
"south",
"east",
"west"
];

answer

```js directions[0][0]; ```

2. We need to use in-between directions, like "east northeast", when navigating. Build the string "east northeast" using this array.

answer

```js directions[2] + " " + directions[0] + directions[2]; ```

3. We can shorten east northeast into shorthand using just the first letters, ene. Build that string using this array.

answer

```js directions[2][0] + directions[0][0] + directions[2][0]; ```