Primitive Types

• Primitive Types
• Boolean type
• Numeric types
  • Integers
  • Floating
  • Complex numbers
• Text types

Boolean type

var n bool = false
var y bool = true

// get boolean by comparing
n := 1 == 1 // true
m := 1 == 2 // false

// every initialized variable has a default 0 value
// bool of 0 is false
var n bool
fmt.Printf("%v, %T", n, n)

Numeric types

Integers

• options
• signed integers
  • int8, int16, int32, int64
• unsigned integers
  • uint8, uint16, uint32, uint64

package main

import ("fmt")

// basic arithmetic operations
func main() {
  a := 10
  b := 3
  fmt.Println(a + b)
  fmt.Println(a - b)
  fmt.Println(a / b)
  fmt.Println(a % b)  
}

package main

import ("fmt")

// basic bit operations
func main() {
  a := 10 // 1010
  b := 3 // 0011
  fmt.Println(a & b) // ANG 1011
  fmt.Println(a | b) // OR 1011
  fmt.Println(a ^ b) // XOR 1001
  fmt.Println(a &^ b)  // AND NOT 1000
}

package main

import ("fmt")

// bit shifting
func main() {
  a := 8 // 2^3
  fmt.Println(a << 3) // 2^3 * 2^3 = 2^6
  fmt.Println(a >> 3) // 2^3 / 2^3 = 2^0
}

Floating

package main

import ("fmt")

// 
func main() {
  a := 3.14
  n = 13.9e10 // declare using exponential notation
}

- same arithmetic operators as integers are available - bit operators are not available

Complex numbers

package main

import ("fmt")


func main() {
  // go parser understands the i literal as an imaginary number
  var n  complex64 = 1 + 2i
  fmt.Printf("%v, %T", n, n)

  var j  complex64 = complex(1, 2)
  fmt.Printf("%v, %T", j, j)

  // isolate the real and imaginary components
  fmt.Printf("%v, %T", real(n), imag(n))
}

- arithmetic operators available

Text types

• string are UTF-8 and immutable

  package main
  
  import ("fmt")
  
  // 
  func main() {
    s := "This is a string"
    fmt.Printf("%v, %T", s, s)
  
    // string can be sliced, type conversion required to get string back
    fmt.Printf("%v, %T", string(s[2]), s)
  
    // concatenation
    s2 := "This is also a string"
    fmt.Printf("%v, %T", s + s2, s + s2)
  
    // convert string to a collection of byes
    b := []byte(s)
    fmt.Printf("%v, %T", s, s)
  }
  

• Rune is UTF-32