Convert from string ascii to string Hex

Question

Suppose I have this string

string str = "1234"

I need a function that convert this string to this string:

"0x31 0x32 0x33 0x34"  

I searched online and found a lot of similar things, but not an answer to this question.

Solution 1

string str = "1234";
char[] charValues = str.ToCharArray();
string hexOutput="";
foreach (char _eachChar in charValues )
{
    // Get the integral value of the character.
    int value = Convert.ToInt32(_eachChar);
    // Convert the decimal value to a hexadecimal value in string form.
    hexOutput += String.Format("{0:X}", value);
    // to make output as your eg 
    //  hexOutput +=" "+ String.Format("{0:X}", value);

}

    //here is the HEX hexOutput 
    //use hexOutput 

Solution 2

This seems the job for an extension method

void Main()
{
    string test = "ABCD1234";
    string result = test.ToHex();
}

public static class StringExtensions
{
    public static string ToHex(this string input)
    {
        StringBuilder sb = new StringBuilder();
        foreach(char c in input)
            sb.AppendFormat("0x{0:X2} ", (int)c);
        return sb.ToString().Trim();
    }
}

A few tips.
Do not use string concatenation. Strings are immutable and thus every time you concatenate a string a new one is created. (Pressure on memory usage and fragmentation) A StringBuilder is generally more efficient for this case.

Strings are array of characters and using a foreach on a string already gives access to the character array

These common codes are well suited for an extension method included in a utility library always available for your projects (code reuse)

Solution 3

Convert to byte array and then to hex

        string data = "1234";

        // Convert to byte array
        byte[] retval = System.Text.Encoding.ASCII.GetBytes(data);

        // Convert to hex and add "0x"
        data =  "0x" + BitConverter.ToString(retval).Replace("-", " 0x");

        System.Diagnostics.Debug.WriteLine(data);

Solution 4

A nice declarative way to solve this would be:

var str = "1234"

string.Join(" ", str.Select(c => $"0x{(int)c:X}"))

// Outputs "0x31 0x32 0x33 0x34"

Solution 5

static void Main(string[] args)
{
    string str = "1234";
    char[] array = str.ToCharArray();
    string final = "";
    foreach (var i in array)
    {
        string hex = String.Format("{0:X}", Convert.ToInt32(i));
        final += hex.Insert(0, "0X") + " ";       
    }
    final = final.TrimEnd();
    Console.WriteLine(final);
}

Output will be;

0X31 0X32 0X33 0X34

Here is a DEMO.

View more solutions

Comments

[Daniel Hilgarth]

That outputs 0x1, 0x2, 0x3, 0x4. Not what the OP wants.

[Daniel Hilgarth]

You should delete the first, incorrect version. And you should fix the second one. It produces the correct output, but the format should look like this: string.Format("0x{0:X2}", (int)s). Reasons: (1) X8 is never used, because the value used for this parameter is a string. (2) A char can contain values that exceed the range of a byte.

[Davut Gürbüz]

I just desired to show string.Format and ToString() together. I supposed chars in ASCII. byte is enough for ascii AFAIK. thanks.

[Laurynas Lazauskas]

Note that this uses string concatenation, which might or might not be a performance problem depending on the size of str.