## Kotlin Subtraction Assignment Operator

Kotlin Subtraction Assignment Operator assigns left operand with the subtraction of left operand from right operand.

### Syntax

The syntax to use Subtraction Assignment operator is

`x -= value`

where

`x`

is the variable name`-=`

is the symbol used for Subtraction Assignment operator`value`

is the value that we would like to subtract from that of in variable`x`

The above expression is equivalent to

`x = x - value`

## Examples

### Decrement the value in x by 10

In the following program, we take a variable: `x`

with an initial value of `21`

. Using Addition Assignment operator, we decrement the value in `x`

by `10`

.

**Kotlin Program**

```
fun main() {
var x = 21
x -= 10
println(x)
}
```

**Output**

`11`

**Explanation**

```
x -= 10
x = x - 10
x = 21 - 10
x = 11
```