Kotlin convert string to byte array

Example Kotlin Code for Converting Strings to Byte Arrays

As a possible solution, consider creating a simple function and utilizing it. Alternatively, if all the bytes are less than or equal to a certain value, they can be added directly. For bytes greater than this value, unsigned literals can be used to create a new value and then converted back into a byte. This method is preferable to appending at each element and eliminates the need for a custom function. However, it is important to note that Kotlin’s bytes are signed and can only represent values within the range of -128 to 127.

Kotlin convert hex string to ByteArray

You can handle it like this:

fun String.decodeHex(): ByteArray < check(length % 2 == 0) < "Must have an even length" >return chunked(2) .map < it.toInt(16).toByte() >.toByteArray() > 

1. Divide the string into pairs of 2 characters, representing individual bytes.
2. Convert each set of hexadecimal digits into their corresponding integer values.
3. Transform the analyzed Int into Bytes .

The most straightforward approach I suggested generates two temporary lists, one containing strings and the other containing bytes, before constructing the final byte array. However, for greater efficiency, there are two more intricate alternatives that can be considered.

Utilizing lazy evaluation, this edition employs sequences, without any intermediate lists, to generate a string for each byte.

fun String.decodeHex(): ByteArray < check(length % 2 == 0) < "Must have an even length" >val byteIterator = chunkedSequence(2) .map < it.toInt(16).toByte() >.iterator() return ByteArray(length / 2) < byteIterator.next() >> 

The JDK’s java.lang.Integer.parseInt function is employed by this version to generate the ByteArray directly, bypassing any intermediary data-structures.

fun String.decodeHex(): ByteArray < check(length % 2 == 0) < "Must have an even length" >return ByteArray(length / 2) < Integer.parseInt(this, it * 2, (it + 1) * 2, 16).toByte() >> 

Kotlin Program to Convert Character to String and Vice, We use String’s toCharArray() method to convert the string to an array of characters stored in chars. We then, use Arrays’s toString() method to print the elements of chars in an array like form. Here’s the equivalent Java code: Java program to convert char to string and vice-versa

Creating ByteArray in Kotlin

It is possible to generate a basic function as a choice.

fun byteArrayOfInts(vararg ints: Int) = ByteArray(ints.size) < pos ->ints[pos].toByte() > 

val arr = byteArrayOfInts(0xA1, 0x2E, 0x38, 0xD4, 0x89, 0xC3) 

In case your bytes are below or equal to 0x7F , it is possible to directly place them.

In case you require the utilization of bytes exceeding 0x7F , it is possible to generate an unsigned literal to form a UByteArray , and subsequently, transform it back into a ByteArray .

ubyteArrayOf(0xA1U, 0x2EU, 0x38U, 0xD4U, 0x89U, 0xC3U).toByteArray() 

Instead of adding .toByte() to each element, which can be cumbersome, there is no requirement to create a personalized function to achieve the same outcome.

Kotlin’s unsigned types are not fully developed and may generate warnings.

The problem lies in the fact that Kotlin’s bytes are signed, which restricts them to values within the [-128, 127] range. To demonstrate this, one can create a ByteArray as shown below.

val limits = byteArrayOf(-0x81, -0x80, -0x79, 0x00, 0x79, 0x80) 

An error will be generated only for the initial and final values, as they exceed the acceptable range by one.

The behavior observed in Java is identical, and to address it, one may need to employ a bigger numerical data type if the values being used surpass the capacity of Byte or adjust them by 128, among other options.

Please take note that once you use toInt to generate an array and print its contents, you may observe that any value exceeding 127 has been transformed into a negative number.

val bytes = byteArrayOf(0xA1.toByte(), 0x2E.toByte(), 0x38.toByte(), 0xD4.toByte(), 0x89.toByte(), 0xC3.toByte()) println(bytes.joinToString()) // -95, 46, 56, -44, -119, -61 

How to convert a ByteArray to a ShortArray in Kotlin?, For example (editing the above to return correct answers): val byteArray = byteArrayOf (211.toByte (), 0, 24, 0) val shortArray = ShortArray (byteArray.size / 2) < (byteArray [it * 2].toUByte ().toInt () + (byteArray [ (it * 2) + 1].toInt () shl 8)).toShort () >println (shortArray.toList ()) // [211, 24]

How to convert String to String array in Kotlin?

val str = "abcd" val array: Array = str.toCharArray().map < it.toString() >.toTypedArray() 

val str = "Hello" val arr = str.split("") fun main() < println(arr) // [, H, e, l, l, o] >

An array can be filled while initializing it by utilizing a lambda function that accepts the index as a parameter.

Creating ByteArray in Kotlin, The issue is that bytes in Kotlin are signed, which means they can only represent values in the [-128, 127] range. You can test this by creating a ByteArray like this: val limits = byteArrayOf(-0x81, -0x80, -0x79, 0x00, 0x79, 0x80) Only the first and last values will produce an error, because they are out of the …

Convert Byte Array to String in Kotlin

val md5 = MessageDigest.getInstance("MD5") val hash = BigInteger(1, md5.digest(queryToSign.toByteArray(Charset.defaultCharset()))).toString(16) 

Android — Convert Byte Array to String in Kotlin, Convert Byte Array to String in Kotlin. Ask Question Asked 4 years, 9 months ago. Modified 3 years, 10 months ago. Viewed 3k times 6 2. I’m trying to generate MD5 of a string in my android code using kotlin.. val md5 = MessageDigest.getInstance(«MD5») val hash = …

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Kotlin String to Byte Array: The Complete Guide for Effective Manipulation

Learn how to convert a string to a byte array in Kotlin using different methods. Explore the best practices for working with byte arrays and strings. Get ready to manipulate byte arrays effectively!

• Using toByteArray() method
• Using String() constructor
• Working with ByteArray class
• Encoding and decoding byte arrays
• Adding hexadecimal methods
• Other quick code examples for converting Kotlin strings to byte arrays
• Conclusion
• How to convert string into byte array in Kotlin?
• How do you convert a string to a byte array?
• How to create byte array in Kotlin?
• How do you create an empty byte array in Kotlin?

converting a string to a byte array is a common task in programming, and Kotlin provides several methods to accomplish this. In this guide, we will explore the different ways to convert a string to a byte array in Kotlin and the best practices for working with byte arrays and strings. By the end of this guide, you will have a solid understanding of how to convert strings to byte arrays in Kotlin and how to work with them effectively.

Using toByteArray() method

The toByteArray() method in Kotlin allows us to convert a string to a byte array using UTF-8 Charset. This method encodes the contents of the string using the specified character set and returns the resulting byte array.

val byteArray = "Hello World".toByteArray() 

The toByteArray() method is the simplest and most common way to convert a string to a byte array in Kotlin. It’s easy to use and works well for most situations.

Using String() constructor

The String() constructor in Kotlin can be used to convert a byte array to a string using the specified charset. This constructor takes a byte array and a Charset as arguments and returns a string.

val byteArray = byteArrayOf(72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100) val charset = Charsets.UTF_8 val string = String(byteArray, charset) 

The String() constructor is useful when you have a byte array that you want to convert to a string. It’s important to specify the correct charset, or you may end up with unexpected results.

Working with ByteArray class

The ByteArray class in Kotlin represents an array of bytes and has several methods for working with bytes. The all() method can be used to check if all elements match a predicate, and the toUByteArray() method can be used to convert to an array of UByte.

val byteArray = byteArrayOf(1, 2, 3, 4, 5) val allMatch = byteArray.all < it < 10 >val uByteArray = byteArray.toUByteArray() 

The ByteArray class is useful when you’re working with byte arrays and need to perform operations on them. The all() method is particularly useful when you want to check if all elements in a byte array meet a certain condition.

Encoding and decoding byte arrays

Kotlin provides several methods for encoding and decoding strings and byte arrays. The readBytes() method can be used to read the entire content of a file or URL as a byte array in Kotlin. The ByteString class in Kotlin specifies that a ByteArray shall be encoded/decoded as CBOR major type 2: a byte string.

val file = File("example.txt") val byteArray = file.readBytes() val byteString = ByteString(byteArray) 

The ByteString class is useful when you’re working with byte arrays and need to encode/decode them in a specific way. The readBytes() method is useful when you want to read the entire contents of a file or URL as a byte array.

Adding hexadecimal methods

ByteArray and String extensions can be used to add hexadecimal methods in Kotlin. The toHex() and toHex2() methods can be used to convert byte arrays to hex strings in Kotlin.

fun ByteArray.toHex(): String = joinToString("") < "%02x".format(it) >fun String.toHex2(): String = toByteArray().joinToString("")

The toHex() and toHex2() methods are useful when you want to convert byte arrays to hex strings. They make it easy to work with byte arrays and convert them to a more readable format.

Other quick code examples for converting Kotlin strings to byte arrays

In Kotlin , kotlin string to bytes code sample

Conclusion

In conclusion, Kotlin provides several methods for converting strings to byte arrays and working with them effectively. By using the toByteArray() method, String() constructor, ByteArray class, and encoding/decoding methods, we can easily manipulate byte arrays in Kotlin. Remember to use the appropriate character set and encoding/decoding methods for the desired outcome, and be aware of common issues when working with byte arrays.

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How to convert a string to byte array in Kotlin

In this post, we will learn how to convert a string to a byte array in Kotlin. The String class provides a method called toByteArray in Kotlin that we can use to convert a string to a byte array. We will learn the syntax of this method and how to use it to convert a string to byte array.

The toByteArray method is defined as like below:

fun str.toByteArray(charset: Charset = Charsets.UTF_8): ByteArray

This method can be called on any string variable. It takes one optional parameter. This is the character set to use for the string-byte array conversion. By default, it is UTF-8.

Let’s try the toByteArray method with an example:

fun main()  val givenString = "Hello World !!" val byteArray = givenString.toByteArray() println("Byte Array: $byteArray.contentToString()>") >

Here, we are converting the string givenString to a byte array. The contentToString() method returns a string representation of the byte array.

If you run this program, it will print:

: [72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100, 32, 33, 33]

We can also convert the byte array to a string to check if the conversion is correct.

fun main()  val givenString = "Hello World !!" val byteArray = givenString.toByteArray() println("Byte Array: $byteArray.contentToString()>") println("Original String: $byteArray.toString(Charsets.UTF_8)>") >

The second print statement will print the original string. We are passing Charsets.UTF_8 to the toString() method as this is the default Charsets used with toByteArray.

Example to use toByteArray with different Charsets:

Let’s try toByteArray with a different Charsets:

fun main()  val givenString = "Hello World !!" val byteArray = givenString.toByteArray(Charsets.US_ASCII) println("Byte Array: $byteArray.contentToString()>") println("Original String: $byteArray.toString(Charsets.US_ASCII)>") >

It uses US_ASCII. The program will print the same output as we are printing the string representation of the byte array. The byte array data will be different.

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