Go Syntax

A Go program consists of several key components arranged in a structured way. These components include:

1. Package Declaration: This defines the package to which the file belongs.
2. Importing Packages: External functionalities are made available by importing relevant packages.
3. Functions: These are blocks of reusable code designed to perform specific tasks.
4. Statements and Expressions: These provide the logic and instructions executed by the program.

Example:

package main

import ("fmt")

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

package main

​

import ("fmt")

​

func main() {

  fmt.Println("Hello World!")

}

Explanation of the Example Code

1. Package Declaration (Line 1): In Go, every program is part of a package. This is declared using the package keyword. The file belongs to the main package, which is mandatory for any Go program meant to be executed.
2. Import Statement (Line 2): The import ("fmt") statement allows access to the fmt package. This package provides various functions for text formatting and printing.
3. Whitespace (Line 3): Go ignores extra white space. A blank line, such as this one, is used to improve the readability of the code.
4. Main Function (Line 4): The func main() {} defines the main function. This is the starting point of any Go program. The code enclosed within {} is executed when the program runs.
5. Statement (Line 5): The fmt.Println() function from the fmt package is used to print text to the console. In this case, it displays “Hello World!” when executed.

Go Statements and Syntax Rules

• A statement in Go, like fmt.Println("Hello World!"), represents a complete instruction for the program to execute.
• Statements can terminate with a newline (pressing Enter) or a semicolon (;). However, in Go, semicolons are implicitly added at the end of a statement, so they are rarely seen in the source code.
• Curly Bracket Placement: The opening { must be on the same line as the function declaration.

Example of Incorrect Syntax:

package main

import ("fmt")

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

package main

​

import ("fmt")

​

func main()

{

  fmt.Println("Hello World!")

}

This code will throw an error because the { is placed on a new line, violating Go’s syntax rules.

Compact Go Code

Although Go allows all code to be written on a single line, this approach is strongly discouraged, as it can reduce readability.

Example of Compact Code:

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

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

While the above code runs correctly, it’s harder to read and should be avoided in practice.