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How to convert a string to a hexadecimal representation in Kotlin

How to convert a string to a hexadecimal representation in Kotlin.

Here's a step-by-step tutorial on how to convert a string to a hexadecimal representation in Kotlin:

Step 1: Declare the input string​

To begin, declare the string that you want to convert to a hexadecimal representation. For example, let's say we have the following string:

val inputString = "Hello World"

Step 2: Convert the string to a byte array​

Next, convert the input string to a byte array. This is necessary because hexadecimal representation is commonly used to represent binary data, and each character in a string can be represented by one or more bytes. To convert the string to a byte array, you can use the toByteArray() function:

val byteArray = inputString.toByteArray()

Step 3: Convert each byte to a hexadecimal string​

Now, iterate over each byte in the byte array and convert it to its hexadecimal representation. In Kotlin, you can use the format() function with the %02X format specifier to achieve this. The %02X specifier formats the byte as a two-digit hexadecimal number with leading zeros if necessary:

val hexStringBuilder = StringBuilder()
for (byte in byteArray) {
    val hexString = "%02X".format(byte)
    hexStringBuilder.append(hexString)
}
val hexString = hexStringBuilder.toString()

Step 4: Print or use the hexadecimal representation​

Finally, you can either print or use the resulting hexadecimal representation as needed. In this example, let's print the hexadecimal representation of the input string:

println(hexString)

Putting it all together, here's the complete example:

fun main() {
    val inputString = "Hello World"
    val byteArray = inputString.toByteArray()

    val hexStringBuilder = StringBuilder()
    for (byte in byteArray) {
        val hexString = "%02X".format(byte)
        hexStringBuilder.append(hexString)
    }
    val hexString = hexStringBuilder.toString()

    println(hexString)
}

When you run this code, it will output the hexadecimal representation of the input string "Hello World":

48656C6C6F20576F726C64

That's it! You have successfully converted a string to its hexadecimal representation in Kotlin.