# Scala Comparators

A few new concepts are needed for this SKB.

First, what is a `Boolean`? A `Boolean` can only take two values: `true` or `false`. It is the result of a mathematical question. For instance, is 2 less than 5 (`2 < 5`), it would returns "yes" (`true`).

And from previous SKB, you might have noticed that `assert` tests if what is inside is `true`.

In Scala, and in the majority of other programming languages, you have a series of built-in comparators for mathematics:

• `==` : for equality. Some tips here:
• Notice that there are two `==`. With only one `=`, it would be an assignation (Like in: `val a = 2`).
• In your projects as a software engineer, always be careful about comparing numbers with decimals (Like `1.5632426546`, they are called `Double` or `Float`) because the computer will round those numbers. So instead of `a == b`, you should be doing something like: `Math.abs(a - b) < 0.01`.
• `!=` : Not equal
• `>` : Greater than
• `<` : Less than
• `>=` : Greater than or equal
• `<=` : Less than or equal