# Numbers

on Saturday, 18th of July, 2020

Dart supports sever built in types. These are the most common of the types that represent a single value.

- int
- double
- num
- String
- bool

### int

An `int`

is a whole number (integer).

```
int one = 1;
int age = 45;
int year = 2020;
// an int can be negative
int balance = -45;
```

### double

A `double`

is a floating-point number, or a number with a decimal point.

```
double percent = .65;
double rating = 4.5;
// a double can be negative
double negativeNumber = -87.42;
```

### num

`num`

is a super class of both `int`

and `double`

. Which means you can use `num`

when dealing with numbers that could be an integer or floating-point number. They're best used when you don't know which of the types will be used.

```
num sum;
// now sum has an int value
sum = 4 + 5;
// by adding a double, sum now refers to a double value
sum = sum + 5.5;
```

- previous: dynamic