What are the basic types in Go or Golang?

Originally posted here!

There are a total of 19 basic types in Go or Golang. Those are mentioned below:

• bool
• string
• int
• int8
• int16
• int32
• int64
• uint
• uint8
• uint16
• uint32
• uint64
• uintptr
• byte
• rune
• float32
• float64
• complex64
• complex128

bool type

The bool type is used for holding truthy/falsy values such as true or false.

var isAdmin bool // isAdmin variable has a type of `bool`
isAdmin = true

string type

The string type is used to hold a sequence of characters. The characters are enclosed in double quotation marks symbol ("").

var name string // name variable has a type of `string`
name = "John Doe"

int, int8, int16, int32, and int64 type

The int types are used to hold numerical values including the negative and non-negative numbers.

The numbers after the word int refer to the size. For example, the int8 type can hold values of 8-bit size.

Each of the int types can have negative and non-negative numbers up to a certain range. These are mentioned below:

• The int8 type can have numbers ranging from -128 to 127.
• The int16 type can have numbers ranging from -32768 to 32767.
• The int32 type can have numbers ranging from -2147483648 to 2147483647.
• The int64 type can have numbers ranging from -2^63 (-2 to the power of 63) to 2^63 - 1 (2 to the power of 63 minus 1).
• The int type is a platform-dependent type which means that on a 32 bit system it will be the same as the int32 type and on a 64 bit system it will be the same as the int64 type.

var num int8 // num variable has a type of `int8`
num = -128

uint, uint8, uint16, uint32, and uint64 type

The uint types are used to hold numerical values for non-negative numbers. It is also called as unsigned integer type.

The numbers after the word int refer to the size. For example, the uint8 type can hold values of 8-bit size.

Each of the uint types can have non-negative numbers up to a certain range. These are mentioned below:

• The uint8 type can have numbers ranging from 0 to 255.
• The uint16 type can have numbers ranging from 0 to 65535.
• The uint32 type can have numbers ranging from 0 to 4294967295.
• The uint64 type can have numbers ranging from 0 to 2^64 - 1 (2 to the power of 64 minus 1).
• The uint type is a platform-dependent type which means that on a 32 bit system it will be the same as the uint32 type and on a 64 bit system it will be the same as the uint64 type.

var num uint8 // num variable has a type of `uint8`
num = 255

uintptr type

You may never have to use the uintptr type unless you are developing code related to Go runtime libraries. It is used to bypass the Go's type system and can be used as the reference of memory locations of C or other system-level programming languages codes.

byte type

The byte is an alias for the uint8 type.

rune type

The rune is an alias for the int32 type.

One cool thing with the rune type is that if you assign a Unicode symbol like 😃 (Smiling Face with Open Mouth) to the variable, then it will be automatically converted into its hexadecimal Unicode codepoint. The hexadecimal is essentially an integer.

var favEmoji rune
favEmoji = '😃'
fmt.Println(favEmoji) // 128515

float32 and float64 type

The float32 and float64 type is used to hold numerical values having a decimal or fractional part.

• The float32 type has a 32 bit size and has single precision.
• The float64 type has a 64 bit size and has double precision.

floatNum := 78.65 // floatNum variable has the type of float64

complex64 and complex128 type

Go can easily handle complex numbers also with the complex64 and complex128 types.

• The complex64 type has a real part composed of the float32 type and an imaginary part composed of the float32 type.
• The complex128 type has a real part composed of the float64 type and an imaginary part composed of the float64 type.

It can be done like this,

complexNum := 5 + 8i // complexNum variable type is complex128

Or you can use the built-in complex() function to create the real and imaginary parts of a complex number like this,

complexNum := complex(5, 8) // complexNum variable type is complex128
fmt.println(complexNum) // 5 + 8i

These are the available basic types in Golang.

That's all 😃!

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