解析文件中的每一行之后，scanner.Text（）的类型是什么？

I am currently reading a text file input.txt with the following inputs:

123
456
789

The code to parse it is:

package main

import (
    "bufio"
    "fmt"
    "os"
)

func main() {
    file, err := os.Open("input.txt")
    if err != nil {
        log.Fatal(err)
    }   
    defer file.Close()

    scanner := bufio.NewScanner(file)
    count := 0
    var line string
    for scanner.Scan() {
        count += 1
        line = scanner.Text()
        fmt.Println(line)
        if line == "123" {
            fmt.Println("EQUAL")
        }   
    }
}

Why does the first line of the file not match the hard coded string 123 in the code?

As mentioned in the comments, this is due to special characters in the file. In this case the utf8 bom, but could be dos format , or other non-printable characters.