You don't need to update your GoLand! Comma, not colon, just spelling error. The code is on the screen. fmt.Printf() formatting values guide: %s - string values, %g - float values (like 1.0, 2.3), %o - integer values, %t - boolean values (true or false), %e - scientific notations, More at https://www.geeksforgeeks.org/fmt-printf-function-in-golang-with-examples/
