Convert Hexadecimal to Decimal and Decimal to Hexadecimal in Golang

Decimal Number System

Decimal number system is the standard system for denoting integers and non-integers numbers.
This is also known as base 10 number system.

0 1 2 3 4 5 6 7 8 9

Hexadecimal Number System

Hexadecimal (mostly used as hex) number system use 16 symbols. It is known as base 16 number system, where 10 symbols are same as decimal and value greater than 9 represent as A=10, B=11, C=12, D=13, E=14, F=15.

0 1 2 3 4 5 6 7 8 9 A B C D E F

Convert Hexadecimal to Decimal

Golang package strconv provides ParseInt and ParseUint to convert the string to the number in the respective base. Hexadecimal numbers are commonly use 0x or 0X in front of the number. It is only to avoid confusion.

Syntax

func ParseInt(s string, base int, bitSize int) (i int64, err error)

package main

import (
    "fmt"
    "strconv"
)

func main() {
    hexa := "F1"

    decimal, err := strconv.ParseInt(hexa, 16, 32)

    if err != nil {
        fmt.Println(err)
    }

    fmt.Printf("Hexadecimal %s (base16) = Decimal %v (base10)", hexa, decimal)
}

Output

Hexadecimal F1 (base16) = Decimal 241 (base10)

The ParseUint is same as ParseInt but it takes only unsigned integers. To remove the 0x or 0X from the hex number, you can use slices.

hexa := "0xfc"
hexa = hexa[2:]

Convert Decimal to Hexadecimal

The same strconv package provides FormatInt and FormatUint to convert the decimal number to a respective base number.

package main

import (
    "fmt"
    "strconv"
)

func main() {
    var decimal int64 = 252

    hexa := strconv.FormatInt(decimal, 16)

    fmt.Printf("Decimal %v (base10) = Hexadecimal %s (base16)", decimal, hexa)
}

The FormatUint is same as FormatInt but it takes only unsigned integers.

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For negative numbers use - minus sign.

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