pmareke/go-notes

Notes and exercises of my journey learning Go

GO Notes

Resources

• Learn Go with Tests
• Go Exercism track
• Go Koans
• Go Documentation
• Effective Go
• Go by Example

Basics

• Go is a statically typed, compiled programming language.
• All source files in a directory must share the same package name.
• When a package is imported, only entities whose names start with a capital letter can be used / accessed.
• Variables can be defined by explicitly specifying a type.
• You can also use an initializer, and the compiler will assign the variable type to match the type of the initializer.
• Constants are defined using the const.
• Go functions accept zero or more parameters.
  • Parameters must be explicitly typed, there is no type inference.
• Values are returned from functions using the return keyword.

Comments

• Go supports two types of comments:
  • Single line comments are preceded by //.
  • Multiline comments are inserted between /* and */.
• They are used by the godoc command.
• A documentation comment should be a complete sentence that starts with the name of the thing being described and ends with a period.
• Comments should precede packages as well as exported identifiers.

Numbers

• Go contains basic numeric types that can represent sets of either integer or floating-point values.
  • uint: the set of all unsigned integers.
  • int: the set of all integers.
  • float: the set of all floating-point numbers
  • complex: the set of all complex numbers.
  • byte: alias for uint8.
  • rune: alias for int32.

Arithmetic Operators

• Arithmetic operations on different types in Go gives an error.
• You can convert the type of a variable using a type conversion.
• It's possible to use x++ or x--.

Booleans

• Booleans in Go are represented by the bool type.
• A bool is either true or false.
• Go supports three boolean operators: ! (NOT), && (AND), and || (OR).
• The preference order is !, &&, and ||.

Iteration

• Go has only one looping construct: the for loop.
• The for loop has three components: the initialization, the condition, and the post statement.
• In Go there are no ( ) surrounding the three components of the for statement.
• The braces { } are always required.

Strings

• A string in Go is an immutable sequence of bytes.
• A string literal is defined between double quotes.
• Strings can be concatenated via the + operator.
• Special characters need to be escaped with a leading backslash.

Conditionals

• Conditionals in Go are similar to conditionals in other languages.
• There are if, else if, and else statements.
• If statements can also include a short initialization statement.

Packages