Data Types in Go

bool

isEarthFlat := false

var isEarthFlat bool
isEarthFlat = false

int — int8, int16, int32, int64

Note: number after int refers to the number of bits for that type - e.g int8 means 8 bit int (+/- 2^8 - 1). int type is a signed integer with at least 32 bits size

temperature := -10
planets := 8

var noOfPlanets int
noOfPlanets = 8

var noOfEyes int8
noOfEyes = 3

uint — uint8, uint16, uint32, uint64

var noOfPlanets uint
noOfPlanets = 8

var noOfEyes uint8
noOfEyes = 3

uintptr

Note: uintptr is an integer type that is large enough to hold the bit pattern of any pointer.

float — float32, float64

Note: IEEE-754 floating-point numbers

temperature := -10.2

var height float32
height = 6.2042

var size float64
size = 4.23432423423421212312312131232132132132123

complex — complex64, complex128

Note: Set of all complex numbers with float real and imaginary parts

// 1 is float32, 2 is imaginary is the example below (1 + 2i)
var comp1 complex64 = complex(1, 2)  

// 4 is float32, -6 is imaginary is the example below (4 - 6i)
var comp2 complex64 = complex(4, -6)  

string

empty := ""

fruit := "orange"

var color string
color = "blue"

[] (array)

Note: Collection of data types including struct types

colors := []string{"black", "blue", "green"}

var num [4]int
num[0] = 123
num[1] = 146
num[2] = 158
num[3] = 368

type human struct{
    name string
    age int
    height float32
}

humans := []human{
    {
        name: "akhtar lava",
        age: 50,
        height: 5.92,
    },
    {
        name: "bruce wayne",
        age: 123,
        height: 6.12,
    }
}

// appending to the array
humans = append(humans, human{name:"donald biden", age:212, height:12})

map[k]v

Note: map implementation in Go - Key Value Pairs

// map[key]value

m := make(map[string]int)
m["three"] = 3
m["apple] = 5

// you can retrieve the value and if the key exists in the map
value, exists := m["apple"] // exists is true in this case, value is 5

type human struct{
    name string
    age int
    height float32
}

h := make(map[string]human)
h["akhtar"] = human{
    name: "akhtar",
    age: 50,
    height: 5.92,
}

byte == int8

var b byte = 56

rune == int32

Note: used, by convention, to distinguish character values from integer values

alphabets := "abcdefghijklmnopqrstuvwxyz"
for _, r := range alphabets {
    // r is not a letter - it's the unicode value of the letter, type is rune
    // for a, r == 97
}