This tutorial belongs to the Swift series

We can use a wide set of operators to operate on values.

We can divide operators in many categories. The first is the number of targets: 1 for **unary operators**, 2 for **binary operators** or 3 for the one and only **ternary operator**.

Then we can divide operators based on the kind of operation they perform:

- assignment operator
- arithmetic operators
- compound assignment operators
- comparison operators
- range operators
- logical operators

plus some more advanced ones, including nil-coalescing, ternary conditional, overflow, bitwise and pointwise operators.

Note: Swift allows you to create your own operators and define how operators work on your types you define.

### Assignment operator

The assignment operator is used to assign a value to a variable:

`var age = 8`

Or to assign a variable value to another variable:

```
var age = 8
var another = age
```

### Arithmetic operators

Swift has a number of binary arithmetic operators: `+`

, `-`

, `*`

, `/`

(division), `%`

(remainder):

```
1 + 1 //2
2 - 1 //1
2 * 2 //4
4 / 2 //2
4 % 3 //1
4 % 2 //0
```

`-`

also works as a unary minus operator:

```
let hotTemperature = 20
let freezingTemperature = -20
```

`+`

is also used to concatenate String values:

`"Roger" + " is a good dog"`

### Compound assignment operators

The compound assignment operators combine the assignment operator with arithmetic operators:

`+=`

`-=`

`*=`

`/=`

`%=`

Example:

```
var age = 8
age += 1
```

### Comparison operators

Swift defines a few comparison operators:

`==`

`!=`

`>`

`<`

`>=`

`<=`

You can use those operators to get a boolean value (`true`

or `false`

) depending on the result:

```
let a = 1
let b = 2
a == b //false
a != b //true
a > b // false
a <= b //true
```

### Range operators

Range operators are used in loops. They allow us to define a range:

```
0...3 //4 times
0..<3 //3 times
0...count //"count" times
0..<count //"count-1" times
```

Here’s a sample usage:

```
let count = 3
for i in 0...count {
//loop body
}
```

### Logical operators

Swift gives us the following logical operators:

`!`

, the unary operator NOT`&&`

, the binary operator AND`||`

, the binary operator OR

Sample usage:

```
let condition1 = true
let condition2 = false
!condition1 //false
condition1 && condition2 //false
condition1 || condition2 //true
```

Those are mostly used in the `if`

conditional expression evaluation:

```
if condition1 && condition2 {
//if body
}
```