Getting started

Variables and Assignment

Variable Declaration

# With explicit type
int x = 10
str name = "Velo"

# With any type
any value = 42
value = "Hello"

Semicolons are optional — a newline ends a statement (see Language Basics). This guide mixes both styles; write whichever you prefer.

Immutable Inferred Locals (let)

let name = expr declares a local whose type is inferred from the initializer and which is immutable — it cannot be reassigned. Prefer let for locals you don't mutate:

let x = 42               # int, inferred
let greeting = "Hello"   # str, inferred
# x = 43                 # ERROR: let bindings are immutable

Use an explicit typed declaration (int x = 10) when you need to reassign the variable.

Assignment

int a = 5
a = 10  # Change value
a = a + 1  # Arithmetic operations

Compound Assignment

Velo supports compound assignment operators for concise updates:

int a = 10

a += 5  # Same as: a = a + 5
a -= 3  # Same as: a = a - 3
a *= 2  # Same as: a = a * 2
a /= 4  # Same as: a = a / 4
a %= 3  # Same as: a = a % 3