lesson_3_conditions.md

Lesson 3 - Compare ALL the things

Comparing things beyond numbers

We've learned how to compare numbers with the smaller-than, larger-than operators:

Operator	Example	Result
larger	3 > 1	true
	1 > 3	false
	3 > 3	false
larger equals	3 >= 3	true
smaller	1 < 3	true
	3 < 1	false
	3 < 3	false
smaller equals	3 <= 3	true

They work best with numbers. They do work with strings, though, so it might be a fun excercise to figure out how they work on those.

There are also the "equals" and "not equals" operators, and they have a little quirk in that there are two variations for each, one that automatically converts and one that doesn't:

Operator	Example	Result
Equals	12 == 12	true
	12 == '12'	true
Strict Equals	12 === '12	false
	12 === 12	true
	'12' === '12'	true

Boolean Operators

If you need to combine boolean results (or change them, you can use the boolean operators)

Operator	Code	Result
Not (!)	!true	false
	!false	true
Or (||)	true || true	true
	true || false	true
	false || true	true
	false || false	false
And (&&)	true && true	true
	true && false	false
	false && true	false
	false && false	false

Every side of && and || can be a full expression (which could contain more ANDs and ORs even). Be careful with nesting them too deeply because that can become hard to read, especially since these all have their own precendence rules. For example are you able to guess what the outcome of the following expression is?

(true || false) && (false || true) || (true && false) && false === true

Yeah, me neither.