Convert Byte to Hex and Hex to Byte in Golang

Saturday, July 18, 2020 • 2 minutes to read

In this post of to-the-point series, we will convert a hex string to a byte array and vice-versa. For this, we're going to use the encoding/hex package provided by the golang. Package hex implements hexadecimal encoding and decoding.

byte array to hex string

To convert a byte array to hex string, we will encode the byte array to the hexadecimal string.

Syntax

func EncodeToString(src []byte) string

First we will convert a string to a byte array.

package main

import (
	"encoding/hex"
	"fmt"
)

func main() {
	byteArray := []byte("Learn Go!")
	fmt.Println("byteArray: ", byteArray)

	encodedString := hex.EncodeToString(byteArray)

	fmt.Println("Encoded Hex String: ", encodedString)
}

Output

byteArray: [76 101 97 114 110 32 71 111 33]
Encoded Hex String: 4c6561726e20476f21

Try it

hex string to byte array

To convert hex string to byte array, we will decode the encoded hex string.

Syntax

func DecodeString(s string) ([]byte, error)

We are going to use the same hex string from above.

package main

import (
	"encoding/hex"
	"fmt"
)

func main() {
	hexString := "4c6561726e20476f21"

	fmt.Println("Hex String: ", hexString)

	decodedByteArray, err := hex.DecodeString(hexString)

	if err != nil {
		fmt.Println("Unable to convert hex to byte. ", err)
	}

	fmt.Printf("Decoded Byte Array: %v \nDecoded String: %s", decodedByteArray, decodedByteArray)
}

Try it

Output

Hex String:  4c6561726e20476f21
Decoded Byte Array: [76 101 97 114 110 32 71 111 33]
Decoded String: Learn Go!

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