Develop Reference

Delete part of string value

I want to mix 2 string in 1 randomly using foreach but I don't know how I delete the part I used on the string for the foreach like:
string s = "idontknow";
string sNew = "";
foreach(char ss in s){
s = s + ss;
ss.Delete(s); //don't exist
}
Full code here i'm trying to do:
do
{
if (state == 0)
{
for (int i = 0; random.Next(1, 5) > variable.Length; i++)
{
foreach (char ch in variable)
{
fullString = fullString + ch;
}
}
state++;
}
else if (state == 1)
{
for (int i = 0; random.Next(1, 5) > numbers.Length; i++)
{
foreach (char n in numbers)
{
fullString = fullString + n;
}
}
state--;
}
} while (variable.Length != 0 && numbers.Length != 0);

I'm pretty confident, that in your first code snippet, you are creating an infinite loop, since you are appending the used char back to the string while removing it from the first position.
Regarding your specification to shuffle two stings together, this code sample might do the job:
public static string ShuffleStrings(string s1, string s2){
List<char> charPool = new();
foreach (char c in s1) {
charPool.Add(c);
}
foreach (char c in s2) {
charPool.Add(c);
}
Random rand = new();
char[] output = new char[charPool.Count];
for(int i = 0; i < output.Length; i++) {
int randomIndex = rand.Next(0, charPool.Count);
output[i] = charPool[randomIndex];
charPool.RemoveAt(randomIndex);
}
return new string(output);
}
In case you just want to shuffle one string into another string, just use an empty string as the first or second parameter.
Example:
string shuffled = ShuffleStrings("TEST", "string");
Console.WriteLine(shuffled);
// Output:
// EgsTtSnrTi
There are possibly other solutions, which are much shorter, but I think this code is pretty easy to read and understand.
Concerning the performance, the code above should works both for small stings and large strings.
Since strings are immutable, each modify-operation on any string, e.g. "te" + "st" or "test".Replace("t", ""), will allocate and create a new string in the memory, which is - in a large scale - pretty bad.
For that very reason, I initialized a char array, which will then be filled.
Alternatively, you can use:
using System.Text;
StringBuilder sb = new();
// append each randomly picked char
sb.Append(c);
// Create a string from appended chars
sb.ToString();
And if your question was just how to remove the first char of a string:
string myStr = "Test";
foreach (char c in myStr) {
// do with c whatever you want
myStr = myStr[1..]; // assign a substring exluding first char (start at index 1)
Console.WriteLine($"c = {c}; myStr = {myStr}");
}
// Output:
// c = T; myStr = est
// c = e; myStr = st
// c = s; myStr = t
// c = t; myStr =

repeating the Encrypt function along the length of the bina function

I want to repeat the Encrypt function along the entire length of the bina / how to do it?
private void carbonFiberButton11_Click_1(object sender, EventArgs e)
{
textBox1.Text = PairConcat(Encrypt(), bina());
}
public static string PairConcat(string Encrypt, string bina)
{
StringBuilder result = new StringBuilder();
int i = 0;
for(; i<Encrypt.Length & i < bina.Length; i++)
{
result.Append(Encrypt[i].ToString());
result.Append(bina[i].ToString());
}
result.Append(Encrypt.Substring(i));
result.Append(bina.Substring(i));
return result.ToString();
}
For example:
string bina = "1234567";
string Encrypt = "abcdefg";
textbox1.text = 1a2b3c4d.. ;but it is doesn't works if I have different length:
string bina = "12345"
string Encrypt = "abc"
textbox1.text = 1a2b3c45 , but I need - 1a2b3c4a5b.
Encrypt function:
string Encrypt() //random to binary
{
var encrypt = textBox4.Text;
StringBuilder binary = new StringBuilder();
for (int i = 0; i < encrypt.Length; i++)
{
binary.Append(Convert.ToString(encrypt[i], 2).PadLeft(8, '0'));
}
return binary.ToString();
}
I can't understand what to do/ Help me, please

Just make the Encrypt string in minimum as long as the bina string.
// Calculate smallest multiple of Encrypt.Length at least as long as bina.Length
int lb = bina.Length;
int le = Encrypt.Length;
int bufferLength = (lb + le - 1) / le * le;
var sb = new StringBuilder(Encrypt, bufferLength);
while (sb.Length < lb) {
sb.Append(Encrypt);
}
Encrypt = sb.ToString();
string result = String.Join("", bina.Zip(Encrypt, (a, b) => a.ToString() + b));
The LINQ Zip method combines 2 sequences by providing pairs of items from the two sequences until one sequence ends. Here the sequences consist of chars.
The StringBuilder works most efficiently if does not have to resize its internal buffer. I calculate it by using integer arithmetic.

Reverse a foreach loop action

I want to convert/find each of my string characters to (int) and reverse this operation.
I manage to do the first part,but the seconds one is giving me some problems.
string input;
string encrypt = ""; string decrypt = "";
input = textBox.Text;
foreach (char c in input)
{
int x = (int)c;
string s = x.ToString();
encrypt += s;
}
MessageBox.Show(encrypt);
foreach (int i in encrypt)
{
char c = (char)i;
string s = c.ToString();
decrypt += c;
}
MessageBox.Show(decrypt);
Thanks!

Here is a fixed program according to my advise above
string encrypt = ""; string decrypt = "";
string input = Console.ReadLine();
var length = input.Length;
int[] converted = new int[length];
for (int index = 0; index < length; index++)
{
int x = input[index];
string s = x.ToString();
encrypt += s;
converted[index] = x;
}
Console.WriteLine(encrypt);
for (int index = 0; index < converted.Length; index++)
{
char c = (char)converted[index];
string s = c.ToString();
decrypt += s;
}
Console.WriteLine(decrypt);

This will not work as is, because you're adding numbers to a string with no padding.
Let's assume the first three letter's values are '1','2','3', you'll have a string with "123".
Now, if you know each letter is 1 int length, you're good, but what happens if 12 is valid? and 23?
This might not be a "real" issues in your case because the values will probably be all 2 ints long, but it's very lacking (unless it's homework, in which case, oh well ...)
The ascii values for the alphabet will go from 65 for A to 122 z.
You can either pad them (say 3 chars per number, so 065 for A, and so on), delimit them (have ".", and split the string on that), use an array (like shahar's suggestion), lists, etc etc ...

In Your scenario, encryption may give output as you expected but its hard to decrypt the encrypted text using such mechanism. so I just do some customization on your code and make it workable here.
i suggest a similar one here:
string input;
string encrypt = ""; string decrypt = "";
int charCount = 0;
input = "textBox.Text";
foreach (char c in input)
{
int x = (int)c;
string s = x.ToString("000");
encrypt += s;
charCount++;
}
// MessageBox.Show(encrypt);
while (encrypt.Length > 0)
{
int item = Int32.Parse(encrypt.Substring(0, 3));
encrypt = encrypt.Substring(3);
char c = (char)item;
string s = c.ToString();
decrypt += c;
}
Reason for your code is not working:
You have declared encrypt as string and iterate through each integer in that string value, it is quiet not possible.
if you make that loop to iterate through each characters in that string value again it gives confusion. as :
lets take S as your input. its equivalent int value is 114 so if you make a looping means it will give 1,1,4, you will not get s back from it.

string values to byte array without converting

I'm trying to put the values of a string into a byte array with out changing the characters. This is because the string is in fact a byte representation of the data.
The goal is to move the input string into a byte array and then convert the byte array using:
string result = System.Text.Encoding.UTF8.GetString(data);
I hope someone can help me although I know it´s not a very good description.
EDIT:
And maybe I should explain that what I´m working on is a simple windows form with a textbox where users can copy the encoded data into it and then click preview to see the decoded data.
EDIT:
A little more code:
(inputText is a textbox)
private void button1_Click(object sender, EventArgs e)
{
string inputString = this.inputText.Text;
byte[] input = new byte[inputString.Length];
for (int i = 0; i < inputString.Length; i++)
{
input[i] = inputString[i];
}
string output = base64Decode(input);
this.inputText.Text = "";
this.inputText.Text = output;
}
This is a part of a windows form and it includes a rich text box. This code doesn´t work because it won´t let me convert type char to byte.
But if I change the line to :
private void button1_Click(object sender, EventArgs e)
{
string inputString = this.inputText.Text;
byte[] input = new byte[inputString.Length];
for (int i = 0; i < inputString.Length; i++)
{
input[i] = (byte)inputString[i];
}
string output = base64Decode(input);
this.inputText.Text = "";
this.inputText.Text = output;
}
It encodes the value and I don´t want that. I hope this explains a little bit better what I´m trying to do.
EDIT: The base64Decode function:
public string base64Decode(byte[] data)
{
try
{
string result = System.Text.Encoding.UTF8.GetString(data);
return result;
}
catch (Exception e)
{
throw new Exception("Error in base64Decode" + e.Message);
}
}
The string is not encoded using base64 just to be clear. This is just bad naming on my behalf.
Note this is just one line of input.
I've got it. The problem was I was always trying to decode the wrong format. I feel very stupid because when I posted the example input I saw this had to be hex and it was so from then on it was easy. I used this site for reference:
http://msdn.microsoft.com/en-us/library/bb311038.aspx
My code:
public string[] getHexValues(string s)
{
int j = 0;
string[] hex = new String[s.Length/2];
for (int i = 0; i < s.Length-2; i += 2)
{
string temp = s.Substring(i, 2);
this.inputText.Text = temp;
if (temp.Equals("0x")) ;
else
{
hex[j] = temp;
j++;
}
}
return hex;
}
public string convertFromHex(string[] hex)
{
string result = null;
for (int i = 0; i < hex.Length; i++)
{
int value = Convert.ToInt32(hex[i], 16);
result += Char.ConvertFromUtf32(value);
}
return result;
}
I feel quite dumb right now but thanks to everyone who helped, especially #Jon Skeet.

Are you saying you have something like this:
string s = "48656c6c6f2c20776f726c6421";
and you want these values as a byte array? Then:
public IEnumerable<byte> GetBytesFromByteString(string s) {
for (int index = 0; index < s.Length; index += 2) {
yield return Convert.ToByte(s.Substring(index, 2), 16);
}
}
Usage:
string s = "48656c6c6f2c20776f726c6421";
var bytes = GetBytesFromByteString(s).ToArray();
Note that the output of
Console.WriteLine(System.Text.ASCIIEncoding.ASCII.GetString(bytes));
is
Hello, world!
You obviously need to make the above method a lot safer.

Encoding has the reverse method:
byte[] data = System.Text.Encoding.UTF8.GetBytes(originalString);
string result = System.Text.Encoding.UTF8.GetString(data);
Debug.Assert(result == originalString);
But what you mean 'without converting' is unclear.

One way to do it would be to write:
string s = new string(bytes.Select(x => (char)c).ToArray());
That will give you a string that has one character for every single byte in the array.
Another way is to use an 8-bit character encoding. For example:
var MyEncoding = Encoding.GetEncoding("windows-1252");
string s = MyEncoding.GetString(bytes);
I'm think that Windows-1252 defines all 256 characters, although I'm not certain. If it doesn't, you're going to end up with converted characters. You should be able to find an 8-bit encoding that will do this without any conversion. But you're probably better off using the byte-to-character loop above.

If anyone still needs it this worked for me:
byte[] result = Convert.FromBase64String(str);

Have you tried:
string s = "....";
System.Text.UTF8Encoding.UTF8.GetBytes(s);

Appending Strings in Java/C# without using StringBuffer.Append or StringBuilder.Append

at a recent interview I attended, the programming question that was asked was this. Write a function that will take as input two strings. The output should be the result of concatenation.
Conditions: Should not use StringBuffer.Append or StringBuilder.Append or string objects for concatenation;that is, they want me to implement the pseudo code implementation of How StringBuilder or StringBuffer's Append function works.
This is what I did:
static char[] AppendStrings(string input, string append)
{
char[] inputCharArray = input.ToCharArray();
char[] appendCharArray = append.ToCharArray();
char[] outputCharArray = new char[inputCharArray.Length + appendCharArray.Length];
for (int i = 0; i < inputCharArray.Length; i++)
{
outputCharArray[i] = inputCharArray[i];
}
for (int i = 0; i < appendCharArray.Length; i++)
{
outputCharArray[input.Length + i] = appendCharArray[i];
}
return outputCharArray;
}
While this is a working solution, is there a better way of doing things?

is LINQ legal? strings are just can be treated as an enumeration of chars, so they can be used with LINQ (even though there is some cost involved, see comments):
string a = "foo";
string b = "bar";
string c = new string(a.AsEnumerable().Concat(b).ToArray());
or with your method signature:
static char[] AppendStrings(string input, string append)
{
return input.AsEnumerable().Concat(append).ToArray();
}

You can call CopyTo:
char[] output = new char[a.Length + b.Length];
a.CopyTo(0, output, 0, a.Length);
b.CopyTo(0, output, a.Length, b.Length);
return new String(output);
If they don't like that, call .ToCharArray().CopyTo(...).
You can also cheat:
return String.Join("", new [] { a, b });
return String.Format("{0}{1}", a, b);
var writer = new StringWriter();
writer.Write(a);
writer.Write(b);
return writer.ToString();

I would've done something like the following (argument checking omitted for brevity)
public static string Append(string left, string right) {
var array = new char[left.Length + right.Length];
for (var i = 0; i < left.Length; i++) {
array[i] = left[i];
}
for (var i = 0; i < right.Length; i++) {
array[i + left.Length] = right[i];
}
return new string(array);
}

In Java you can just use concat which does not use StringBuilder or StringBuffer.
String a = "foo";
String b = "bar";
String ab = a.concat(b);
The source for String.concat(String) from Oracle's JDK.
public String concat(String str) {
int otherLen = str.length();
if (otherLen == 0) {
return this;
}
char buf[] = new char[count + otherLen];
getChars(0, count, buf, 0);
str.getChars(0, otherLen, buf, count);
return new String(0, count + otherLen, buf);
}

java default support "+" for append string
String temp="some text";
for(int i=0;i<10;i++)
{
temp=temp+i;
}
Or
temp=temp+" some other text"