Go Syntax

A Go file consists of the following parts

Go Syntax

A Go file consists of the following parts:

  • Package declaration
  • Import packages
  • Functions
  • Statements and expressions
  • Look at the following code, to understand it better:

    Example

    package main
    import ("fmt")

    func main() {
      fmt.Println("Hello World!")
    }

    Example explained

    Line 1: In Go, every program is part of a package. We define this using the package keyword. In this example, the program belongs to the main package.
    Line 2: import ("fmt") lets us import files included in the fmt package.
    Line 3: A blank line. Go ignores white space. Having white spaces in code makes it more readable.
    Line 4: func main() {} is a function. Any code inside its curly brackets {} will be executed.
    Line 5: fmt.Println() is a function made available from the fmt package. It is used to output/print text. In our example it will output "Hello World!".

    Note: In Go, any executable code belongs to the main package.

    Go Statements

    fmt.Println("Hello World!") is a statement.

    In Go, statements are separated by ending a line (hitting the Enter key) or by a semicolon ";".

    Hitting the Enter key adds ";" to the end of the line implicitly (does not show up in the source code).

    The left curly bracket { cannot come at the start of a line.

    Run the following code and see what happens:

    Example

    package main
    import ("fmt")

    func main()
    {
      fmt.Println("Hello World!")
    }

    Go Compact Code

    You can write more compact code, like shown below (this is not recommended because it makes the code more difficult to read):

    Example

    package main; import ("fmt"); func main() { fmt.Println("Hello World!");}

    Go Exercises

    Test Yourself With Exercises

    Exercise:

    Insert the missing part of the code below to output "Hello World".

    package main   
    import ("fmt")
    func main() { ("Hello World!") }

    Start the Exercise