first-steps5 min

Variables and Types

When your program needs to remember something — a name, a score, a temperature — you store it in a variable. In Clean Language, every variable has a type, and you write the type first. This might feel different at first, but it makes your code much easier to read at a glance.

start:
    string name = "Alice"
    integer age = 28
    number height = 1.72
    boolean active = true

    print(name)
    print(age.toString())
    print(height.toString())
    print(active.toString())

Alice
28
1.72
true

Clean Language has four basic types: string for text, integer for whole numbers, number for decimals, and boolean for true/false.

You can change a variable's value after you declare it:

start:
    integer score = 0
    print(score.toString())

    score = 100
    print(score.toString())

0
100

Notice .toString() — whenever you want to print a number or boolean, you convert it to a string first. Clean keeps types strict so mistakes get caught early.

Quick recap

Write the type first, then the name, then the value: integer age = 28
Four basics: string, integer, number, boolean
Use .toString() to convert numbers and booleans for printing
You can reassign a variable anytime — just write variableName = newValue