Lesson
Weekend
## Integers

### Arithmetic Operators

## Terminology

## Examples

## Overview

Letâ€™s look at another common data type: integers. **Integers** represent whole numbers (that is, numbers without decimals). C# integers are similar to the JavaScript integers we used in Intro.

We'll practice working with integers in the REPL. Let's open our REPL with the `$ dotnet-script`

command in the Terminal (for Mac) or GitBash (for Windows).

Now we can create a new integer like this:

```
> 1
1
```

Easy enough! But do notice this is *very* different than:

```
> "1"
"1"
```

The second example is a string *containing* an integer. Strings are the **only** type of data wrapped in quotation marks. If we put quotation marks around a number, it's actually a string...and will act as such!

For instance, check out what happens when we add two numbers wrapped in quotations:

```
> "1" + "1"
"11"
```

1 + 1 isn't 11! But we receive this result because the REPL is actually concatenating two *strings* containing the character `1`

together. You likely already recognize this type of error from JavaScript but it's so common it's worth mentioning again!

We can avoid this erroneous math by avoiding quotation marks and ensuring numerical values are integers like this:

```
> 1 + 1
2
```

That's more like it!

The four **arithmetic operators** we used in JavaScript work the same in C#. You should recall these basic operators:

`+`

for addition, as seen in the example above.`-`

for subtraction.`*`

for multiplication.`/`

for division.

We can use each with integers in the REPL and receive expected results:

**Subtraction**:

```
> 1 - 1
0
```

**Addition:**

```
> 1 + 1
2
```

**Multiplication:**

```
> 2 * 2
4
```

**Division:**

```
> 4 / 2
2
```

**Modulo:**

```
> 5 % 2
1
```

As we discussed in Intro to Programming, a **modulo** gives us the remainder of dividing two numbers. It doesn't have anything to do with percentages!

**Integers**: A type of data representing whole numbers (numbers without decimals).**Operators**: A special character (or characters) that indicates an action to be performed.`+`

,`-`

,`*`

,`/`

, and`%`

are all operators for mathematic functions.

Basic arithmetic works just like you'd expect:

```
1 + 2
4 - 3
5 * 6
9 / 2
7 + 8 * 9
(7 + 8) * 9
```

`9 % 2`

returns the remainder of 9 divided by 2.`%`

is called**modulo**.

Lesson 3 of 5

Last updated more than 3 months ago.