Go Syntax

Basic Structure of a Go Program

Every Go file begins with a package declaration, which tells the compiler which package the file belongs to. Files meant to be run directly must declare package main.

package main

import "fmt"

func main() {
    fmt.Println("Structure matters in Go")
}

The func main Entry Point

When you run a Go program, execution always starts inside func main. There can be only one main function per package main, and it takes no arguments and returns no value.

• Go is case-sensitive: Main and main are different identifiers
• Curly braces { } are required around function and block bodies
• Conditions in if and for statements are not wrapped in parentheses
• The opening curly brace must stay on the same line as the statement above it

package main

import "fmt"

func main() {
    hour := 14
    if hour < 18 {
        fmt.Println("Good afternoon")
    }
}

Semicolons in Go

Go's grammar technically requires a semicolon at the end of every statement, just like C or Java. However, the Go compiler's lexer automatically inserts these semicolons for you at the end of each line, so you almost never type one yourself.

package main

import "fmt"

func main() {
    // Correct: brace stays on the same line
    fmt.Println("This compiles fine")
}

// The following would NOT compile if written as:
// func main()
// {
//     fmt.Println("broken")
// }