---
title: function - Functions and callbacks
summary: Functions can accept and return multiple values. A callback contract belongs to its exact event sender. Do not transfer one event signature to another.
section: reference
kind: guide
status: reference
updated: 2026-10-26
tags: ["API","X4"]
sources: ["https://wiki.egosoft.com/X4%20Foundations%20Wiki/Modding%20Support/","https://www.lua.org/manual/5.1/manual.html","https://luajit.org/ext_ffi_api.html"]
---
## Meaning

Functions can accept and return multiple values. A callback contract belongs to its exact event sender. Do not transfer one event signature to another.

## Example

```lua
local function read_pair()
  return "name", 2
end
local name, count = read_pair()
```

**What happens:** name = "name", count = 2; one function returned two values.

This fragment does not print or write a log message. The values shown are the expected results of the example.

## Methods and related calls

[API reference](wiki:api-index).