Go supports integer data types extensively. Now, we will see what are those.

Signed integers in Go

Signed integer types supported by Go is shown below.

• int8 (8-bit signed integer whose range is -128 to 127)
• int16 (16-bit signed integer whose range is -32768 to 32767)
• int32 (32-bit signed integer whose range is -2147483648 to 2147483647)
• int64 (64-bit signed integer whose range is -9223372036854775808 to 9223372036854775807)

Unsigned integers in Go

• uint8 (8-bit unsigned integer whose range is 0 to 255 )
• uint16 (16-bit unsigned integer whose range is 0 to 65535 )
• uint32 (32-bit unsigned integer whose range is 0 to 4294967295 )
• uint64 (64-bit unsigned integer whose range is 0 to 18446744073709551615 )

Integer Overflow in GoLang

If you assign a type and then use a number larger than the types range to assign it, it will fail. Below is a program trying just that.

package main

import (
	"fmt"
)

func main() {
	var x uint8
        fmt.Println("Throws integer overflow")
	x = 267       // range of uint8 is 0-255
}

Type conversion in GoLang

If you convert to a type that has range lower than your current range, data loss will occur. We do typecast by directly using the name of the variable as a function to convert types.

package main

import (
	"fmt"
)

func main() {
	var x int32
	var y uint32     // range 0 to 4294967295
	var z uint8      // range 0 to 255
	fmt.Println("Type Conversion")
	x = 26700
	y = uint32(x)       // data preserved because number is inside range
	z = uint8(x)        // data loss due to out of range conversion
	fmt.Println(y, z)   // prints 26700 76
}