How do I compare strings in GoLang?

== is the correct operator to compare strings in Go. However, the strings that you read from STDIN with reader.ReadString do not contain "a", but "a\n" (if you look closely, you'll see the extra line break in your example output).

You can use the strings.TrimRight function to remove trailing whitespaces from your input:

if strings.TrimRight(input, "\n") == "a" {
    // ...
}

For the Platform Independent Users or Windows users, what you can do is:

import runtime:

import (
    "runtime"
    "strings"
)

and then trim the string like this:

if runtime.GOOS == "windows" {
  input = strings.TrimRight(input, "\r\n")
} else {
  input = strings.TrimRight(input, "\n")
}

now you can compare it like that:

if strings.Compare(input, "a") == 0 {
  //....yourCode
}

This is a better approach when you're making use of STDIN on multiple platforms.

Explanation

This happens because on windows lines end with "\r\n" which is known as CRLF, but on UNIX lines end with "\n" which is known as LF and that's why we trim "\n" on unix based operating systems while we trim "\r\n" on windows.