letters_and_words

Letters and Words

While we use words without much thought, computers represent data as numbers. In order to store words in a computer we use a data type known as a string. Strings are a list of characters;

Instructions

This set of exercises is intended to be ran within the node REPL

1. Open a terminal and run node
2. Work through each use case and replace ____s with working code.
3. Confirm the output from the command matches the expected output.

Exercises

Knowing the length of a string is useful. Docs for String.length

// The > is the REPL prompt. Don't type it!
> 'hi there'.____; // Replace ____ with working code.
8
> 'what's happening?'.____; // Replace ____ with working code.
17

Let's swap some words around. Docs for String.prototype.replace

// You know the drill.  Replace `____` with appropriate code.
> 'Pretty sure zee is the lamest'.____('lamest', 'coolest');
'Pretty sure zee is the coolest'
> 'Dead men tell no tales'.____('tales', 'rails');
'Dead men tell no rails'

Finding a string inside of another string can be useful. Docs for String.prototype.match

> 'What kind of madness is this?'.____('madness');
[ 'madness',
    index: 13,
    input: 'What kind of madness is this?' ]
> 'When there is nothing you can find'.____('something');
null
> 'You can even use regular expressions!'.____(/(\w{3})/i);
[ 'You'
    index: 0,
    input: 'You can even use regular expressions!' ]

Reflect on: Could you get the location where the found string lives?

Converting strings into a list is helpful in all kinds of situations. Say, turning a comma seperated list into a set of tags for a blog post, CSV parsing or even encryption. Docs for String.prototype.split

> 'Hey there voters!'.____(' ');
[ 'Hey', 'there', 'voters!' ]
> 'Such a character!'.____(''); // Notice an empty string tells JavaScript to split
                                // a string into individual characters.
[ 'S', 'u', 'c', 'h', ' ', 'a', ' ', 'c', 'h', 'a', 'r', 'a', 'c', 't', 'e', 'r', '!' ]
> 'eggs, bacon, cheese, tomato, kale,'.____(____);
[ 'eggs', 'bacon', 'cheese', 'tomato', 'kale,' ]

Reaching into a string to get it's contents based on their location in the string is useful when parsing protocols like HTTP, etc. Docs for String.prototype.slice

> 'Name: Zee'.____(6);
'Zee'
> 'Favorite Color: Chartreuse'.____(____);
'Chartreuse'
> 'Favorite Animal: Catapult'.____(____,3);
'Cat'
> 'Weirdest Trait: Can lick elbow'.____(-14);
'Can lick elbow'

Find the first location of a character. Docs for String.prototype.indexOf

> 'Pork: The Other White Meat'.____(':');
4
> 'Moods: Happy, Sad, Grumpy'.____(',');
12
> 'Friend or foe?'.____('E');
-1

And the last location. Docs for String.prototype.lastIndexOf

> 'Groceries: avacados, bananas, strawberries, oregano'.____(',')
Should evaluate to 42

Lets join some strings together. Docs for String.prototype.concat

> 'Hello'.____('World');
'HelloWorld'
> 'Hey'.____('Thats', 'A', 'Lot','Of', 'Words');
'HeyThatsALotOfWords'

Sometime's we'll want some quotes in our quotes.

> 'They said: ____'Yo____'';
'They said: \'Yo\''
> ____Or you could use a different 'kind' of quotes____;
'Or you could use a different \'kind\' of quotes'

Search suggestion: 'Escaping quotes in JavaScript'

Put It Together!

Open the file questions_and_answers.js and write a function that given a string of the format 'Question: Answer' returns the "Answer" section.

Verify your implementation works by running node questions_and_answers.js.