# Functions inside functions

[Syntax and values](README.md)

A function can contain another function. The inner function remembers the surrounding variables it uses, even after the outer function has finished. This is called a **closure**. Think of the inner function keeping access to its own score card.

It remembers the variables, not a frozen copy of their first values. In the example, the same counter changes `value` on each call, so it prints `11`, then `12`. A new call to `makeCounter` creates a separate counter.

**Lexical environment** means the names available where a function is written. It does not depend on who calls the function. **First-class** means functions are values you can save in a variable, pass to another function, or return. An **anonymous function**, also called a *lambda*, would have no declared name; Pliro currently requires named function declarations.

User functions close over their lexical environment:

```pliro
# language: en
function makeCounter(start):
    let value = start

    function next():
        set value = value + 1
        return value

    return next

let counter = makeCounter(10)
say counter()
say counter()
```

Functions are first-class runtime values: they can be stored, passed, returned,
and called. There is no anonymous-function or lambda syntax.

## Related entries

[Syntax and values](README.md) · [Built-ins](../builtins/README.md) · [Programming guides](../guides/README.md)