> For the complete documentation index, see [llms.txt](https://ineelhere.gitbook.io/code-with-go/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ineelhere.gitbook.io/code-with-go/58-number-parsing.md).

# Number Parsing

This Go code demonstrates the use of the `strconv` package for converting strings to various numeric types. Let's go through the code with inline comments and explanations:

```go
// Importing necessary packages.
import (
	"fmt"
	"strconv"
)

// The main function, where the execution of the program begins.
func main() {
	// Parsing a floating-point number from a string.
	f, _ := strconv.ParseFloat("1.234", 64)
	fmt.Println(f)

	// Parsing an integer from a string.
	i, _ := strconv.ParseInt("123", 0, 64)
	fmt.Println(i)

	// Parsing a hexadecimal integer from a string.
	d, _ := strconv.ParseInt("0x1c8", 0, 64)
	fmt.Println(d)

	// Parsing an unsigned integer from a string.
	u, _ := strconv.ParseUint("789", 0, 64)
	fmt.Println(u)

	// Parsing an integer from a string using Atoi.
	k, _ := strconv.Atoi("135")
	fmt.Println(k)

	// Attempting to parse an invalid string to an integer (results in an error).
	_, e := strconv.Atoi("wat")
	fmt.Println(e)
}
```

#### Output

```
1.234
123
456
789
135
strconv.Atoi: parsing "wat": invalid syntax
```

Explanation:

1. **Parsing a Floating-Point Number:**
   * `strconv.ParseFloat("1.234", 64)` parses the string "1.234" to a floating-point number with a precision of 64 bits.
2. **Parsing an Integer:**
   * `strconv.ParseInt("123", 0, 64)` parses the string "123" to a signed integer with a bit size of 64.
3. **Parsing a Hexadecimal Integer:**
   * `strconv.ParseInt("0x1c8", 0, 64)` parses the string "0x1c8" as a hexadecimal integer with a bit size of 64.
4. **Parsing an Unsigned Integer:**
   * `strconv.ParseUint("789", 0, 64)` parses the string "789" to an unsigned integer with a bit size of 64.
5. **Parsing Integer using Atoi:**
   * `strconv.Atoi("135")` is a shorthand for parsing an integer using `ParseInt` with base 10 and bit size 64.
6. **Parsing an Invalid String (Results in Error):**
   * `strconv.Atoi("wat")` attempts to parse the invalid string "wat" to an integer, resulting in an error.

This code demonstrates the use of `strconv` functions for converting strings to numeric types in Go. It also shows handling errors when parsing invalid strings.