JavaScript Intro to Functions Lab

Objectives

1. Practice writing functions
2. Explain basics of working with strings
3. Explain the difference between return and logging
4. Practice using return and console.log()

Introduction

Welcome to the JavaScript functions lab! You'll notice a few new things in this lesson that we haven't encountered before. Don't worry, we'll walk you through them.

Even if you've walked through some of this material before, it's a good idea to review as we code-along — we're writing functions now, after all.

In this lab, we're writing functions that "speak" at different volumes — they whisper or they shout. We're going to use what we learn practicing speaking in this way to write another function, sayHiToGrandma(), which takes our new-found speaking ability to greet our grandmother. She's not exactly deaf, but whispering can be a bit difficult. But she'll always hear you if you say, "I love you, Grandma."

Note that just like .toUpperCase() changes any string to all uppercase in JavaScript, .toLowerCase() (e.g., 'HELLO'.toLowerCase()) changesany string to all lowercase.

Additionally, how do we check if a string is all lowercase or all uppercase?

var uppercase = "HELLO!"

uppercase.toUpperCase() === uppercase // true

var lowercase = 'hello!'

lowercase.toLowerCase() === lowercase // true

var mixedCase = 'Hi there!'

mixedCase.toLowerCase() === mixedCase // false

mixedCase.toUpperCase() === mixedCase // false

We can simply check whether the string is the same when we convert it to uppercase or lowercase! If it's the same, then it was already in that case; if not, then it's either in the other case or it's mixed case.