# Closure

This Go program demonstrates the use of closures by defining a function that returns another function.

```go
// Importing the "fmt" package, which provides functions for formatted I/O.
import "fmt"

// Function intSeq returns a closure: a function that "closes over" the variable i.
// The returned function can be used to generate a sequence of increasing integers.
func intSeq() func() int {
    // Initialize a variable i.
    i := 0

    // Define and return an anonymous function (closure) that increments and returns i.
    return func() int {
        i++
        return i
    }
}

// The main function, which serves as the entry point for the program.
func main() {
    // Call intSeq, which returns a function that will generate a sequence of integers.
    nextInt := intSeq()

    // Call the returned function, printing the next value in the sequence.
    fmt.Println(nextInt())

    // Call the returned function again, printing the next value in the sequence.
    fmt.Println(nextInt())

    // Call the returned function once more, printing the next value in the sequence.
    fmt.Println(nextInt())

    // Call intSeq again, creating a new closure with its own "i" variable.
    newInts := intSeq()

    // Call the new closure, printing the first value in its own sequence.
    fmt.Println(newInts())
}
```

#### Output

```
1
2
3
1
```

Now, let's break down the code and explain each part:

1. **Function Declarations:**
   * `intSeq() func() int`: This function returns another function (a closure) that generates a sequence of increasing integers. The returned function "closes over" the variable `i`.
2. **Main Function:**
   * `main()`: This is the entry point of the program.
   * `nextInt := intSeq()`: Calls `intSeq`, which returns a closure (a function that increments and returns `i`). The closure is assigned to the variable `nextInt`.
   * `fmt.Println(nextInt())`: Calls the closure (stored in `nextInt`), printing the next value in the sequence.
   * `fmt.Println(nextInt())`: Calls the closure again, printing the next value in the sequence.
   * `fmt.Println(nextInt())`: Calls the closure once more, printing the next value in the sequence.
   * `newInts := intSeq()`: Calls `intSeq` again, creating a new closure with its own `i` variable.
   * `fmt.Println(newInts())`: Calls the new closure, printing the first value in its own sequence.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ineelhere.gitbook.io/code-with-go/15-closure.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.