Declaring Variables

Using the var keyword

var varName type = value

Variables declared without an explicit initial value are given their zero value.

• You must specify either type or value (or both):

  var name string = "John"  // explicit type and value
  var surname = "Doe"       // type is inferred as string
  var age int16             // explicit type, initialized to the zero value (0)

• Declaring multiple variables of the same or different types on a single line:

  var name, age = "John", 30  // mixed types, types inferred
  var a, b, c int = 1, 2, 3   // all must be of the declared type
  var x, y int                // both initialized to the zero value (0)

• Using grouped declaration syntax to declare variables together:

  var (
  	name    string = "John"
  	surname        = "Doe"  // type is inferred as string
  	age     int             // zero value (0)
  )

Using the := syntax

varName := value

Can only be used inside functions, not at the package level.

• Declaring multiple variables on a single line:

  name, age := "John", 30

Using the const keyword

Constants are fixed values that cannot be changed after they are declared. They are read-only.

const varName type = value

• Constants can be declared without explicit types, but they must have values:

  const daysInWeek int = 7  // explicit type and value
  const hoursInDay = 24     // type is inferred as int

• Declaring multiple constants in a single block:

  const (
  	daysInWeek = 7
  	hoursInDay = 24
  )

Computations on constants are mostly done at compile time, not at runtime.