# Other Pages

• Numbers Strings And Booleans

# Goals

• Use the browser's console

• Understand the primitive types of numbers, strings and booleans

# Overview

## Using the Browser's Console

We'll experiment with javascript using the console of our browser. We recommend everyone use Chrome, for consistency through the class.

To open the console on a Mac, use the shortcut `Command` + `Option` + `J`. To open the console in Windows or Linux, use the keyboard shortcut `Control` + `Shift` + `J`. Alternatively, right click, select 'Inspect Element' from the right-click menu, and click the 'Console' tab.

The console is where we can experiment with javascript, by typing after the `>` prompt. The console will also show us the return value of an expression we type and will display any errors we get.

# Step 1

In the console, type `5` and press enter. Notice that it will display the value `5` in response. Thus, our return value for the expression `5` is `5`.

# Step 2

Try `typeof(5)` and note what kind of object `5` is.

# Step 3

Try creating decimal numbers.

# Step 4

Try creating irrational numbers (a number that can only be fully expressed as the ratio of two numbers, like 2/3). Notice that it will convert it to a decimal.

# Step 5

Try adding or subtracting numbers in the console by typing `6 + 12` or `15 - 32`.

# Step 6

Try an edge case with numbers, like `12 / 0`.

# Step 7

To assign a number to a variable, type `favoriteNumber = 5` into the console prompt. Then use favoriteNumber in the next expression, like `favoriteNumber + 7`. Variables in Javascript are traditionally 'camel-cased' with capital letters separating words in a variable name.

# Step 8

More complex math, like exponents, will require us to use the Math object, as in `Math.pow(12, 2)`, but that shouldn't stop us from trying it out!

# Step 9

Bonus Points: Check out Mozilla Developer Network Docs for the Math object, and try using some of the other methods they describe in your console!

## Strings

Strings are units of text, and we encapsulate them in `'single quotes'` or `"double quotes"`.

# Step 10

Try creating a string by typing `'this is a string'` into the console prompt.

# Step 11

You can grab a string's individual characters with `'this is a string'[6]`, where the number 6 is the index of the character you want, starting at 0.

# Step 12

Concatenate strings with `'my name is' + 'Michelle' + '.'`.

# Step 13

Assign a string to a variable by writing `myName = 'Michelle'`.

# Step 14

Use the variable as you would a literal string: `'Is your name ' + myName + '?'`

# Step 15

If you're ahead of others, check out the MDN docs on strings.

## Booleans (True/False)

Booleans are a type of object used to indicate true or false values in Javascript. They are most often used to help check whether a condition is true or not, or whether something exists.

# Step 16

Try creating a Boolean by typing `'x = false'`.

# Step 17

`Type x==false?console.log(`'yes`'):console.log(`'no`');`.