How to read an entire file into a string variable in Go

Hello everyone! I just started learning Go and encountered a seemingly simple task — reading the contents of a text file into a string variable. In other languages (e.g., Python), this is done in one line, but in Go I got confused. I have a file `data.txt` that is located next to the executable file. I want to get its contents as a `string`. Here's what I tried: ```go package main import ( "fmt" "os" ) func main() { file, err := os.Open("data.txt") if err != nil { fmt.Println(err) return } // What next? How to read all the contents? } ``` I see that `os.Open` returns `*os.File`, but I don't understand how to get a string from it. I tried reading byte by byte via `file.Read(buf)`, but you need to know the buffer size in advance.