How to replace a substring within a byte slice using the bytes package in Go?

To replace a substring within a byte slice using the bytes package in Go, you can use the bytes.Replace() function. The bytes.Replace() function takes four arguments: the byte slice, the old substring, the new substring, and the number of replacements to make.

Here's an example that shows how to use bytes.Replace() to replace a substring within a byte slice:

package main

import (
	"bytes"
	"fmt"
)

func main() {
	byteSlice := []byte("Hello, World!")
	oldSubstring := []byte("World")
	newSubstring := []byte("Gopher")
	replaced := bytes.Replace(byteSlice, oldSubstring, newSubstring, 1)

	fmt.Printf("%s\n", replaced)
}

In the example above, the bytes.Replace() function is used to replace the substring "World" with "Gopher" within the byteSlice byte slice. The fourth argument, 1, indicates that only one replacement should be made. The modified byte slice is then printed using fmt.Printf().

When you run the code above, it will output:

Hello, Gopher!

As you can see, the "World" substring has been replaced with "Gopher" within the byte slice.