Assignment Operators

Assignment operators are used to assign values to variables and combine assignment with arithmetic or logical operations.

Simple Assignment

The basic assignment operator (=) assigns a value to a variable.

let x = 10 |
let name = "mq" |
let items = [1, 2, 3]

The update operator (|=) applies an expression to a selected value and updates it in place.

<selector.value> |= expr

The left side specifies what to update using a selector, and the right side is the expression that transforms the value.

# Change the language of all code blocks to rust
.code.lang |= "rust"

# Update a heading level
.h.depth |= 2

Compound assignment operators combine an arithmetic or logical operation with assignment, providing a shorthand for updating variables.

Adds a value to a variable and assigns the result back to the variable.

var x = 10
| x += 5
| x
# => 15

var count = 0
| count += 1
| count
# => 1

Subtracts a value from a variable and assigns the result back to the variable.

var x = 10
| x -= 3
| x
# => 7

var balance = 100
| balance -= 25
| balance
# => 75

Multiplies a variable by a value and assigns the result back to the variable.

var x = 5
| x *= 3
| x
# => 15

var price = 100
| price *= 1.5
| price
# => 150

Divides a variable by a value and assigns the result back to the variable.

var x = 20
| x /= 4
| x
# => 5

var total = 100
| total /= 2
| total
# => 50

Computes the remainder of dividing a variable by a value and assigns the result back to the variable.

var x = 17
| x %= 5
| x
# => 2

var count = 23
| count %= 10
| count
# => 3

Divides a variable by a value, floors the result (rounds down to the nearest integer), and assigns it back to the variable.

var x = 17
| x //= 5
| x
# => 3

var count = 23
| count //= 10
| count
# => 2