Insert a number between characters of a string

[srikanth2321]

Hi,

I'm trying to insert a number between a string.

For e.g. : If I have a string like "C23H24N1O" or "CHAl"

Then it should be "C23H24N1O1" or "C1H1Al1"

If a capital letter doesn't carry any numerical then it should insert "1" next to it

If a capital letter carry a small letter (for e.g. "Na") and if this small letter doesn't carry any number then it should insert "1" (for e.g. "Na1")

If these carry numbers then no alterations should be made.

private void button17_Click(object sender, EventArgs e)
        {
            textBox5.Clear();
            for (int i = 0; i < textBox4.Text.Length; i++)
            {
                if ((textBox4.Text[i] >= 'A') && (textBox4.Text[i] <= 'Z'))
                {
                    textBox5.AppendText(textBox4.Text[i].ToString());
                    if ((textBox4.Text[i + 1] >= 'A') && (textBox4.Text[i + 1] <= 'Z') || (textBox4.Text[i + 1] >= ' '))
                    {
                        try
                        {
                            if ((textBox4.Text[i + 1] >= 'a') && (textBox4.Text[i + 1] <= 'z'))
                            {
                                if ((Convert.ToInt32(textBox4.Text[i + 2]) >= 1) && ((Convert.ToInt32(textBox4.Text[i + 2]) <= 9)))
                                {
                                    textBox5.AppendText(textBox4.Text[i + 1].ToString() + textBox4.Text[i + 2].ToString());
                                }
                                else
                                {
                                    textBox5.AppendText(textBox4.Text[i + 1].ToString() + "1");
                                }
                            }
                            else if ((textBox4.Text[i + 1] >= 'A') && (textBox4.Text[i + 1] <= 'Z'))
                            {
                                if ((textBox4.Text[i + 2] >= 'a') && (textBox4.Text[i + 2] <= 'z'))
                                {
                                    textBox5.AppendText(textBox4.Text[i + 2] + "1");
                                }
                                else
                                {
                                    textBox5.AppendText("1");
                                }
                            }
                        }
                        catch { }
                    }
                    else
                    {
                        textBox5.AppendText(textBox4.Text[i+1].ToString());
                    }
                }
                else 
                {
                    textBox5.AppendText(textBox4.Text[i].ToString());
                }
               
            }
        }

This this what I have tried but still there is some functionality missing.

Please help me..

regards,
Srik

[ddanbe]

Perhaps you could make use of the fact that in the periodic table only 13 elements have 1 letter al the rest have two or three(rare).
Could you elaborate on the fact you use two textboxes?

[srikanth2321]

Perhaps you could make use of the fact that in the periodic table only 13 elements have 1 letter al the rest have two or three(rare).
Could you elaborate on the fact you use two textboxes?

Hi,

Thanks for the reply.

One is the text box (textbox4) which contains the formula and the other is just to display the result (textbox5)

[ddanbe]

Some other things from the char class may come in handy: http://msdn.microsoft.com/en-us/library/424s1h3z.aspx
Have a look at the isDigit(string, Int32) and IsLower(string, Int32) methods.

[Momerath]

using System;
using System.Text;
using System.Text.RegularExpressions;

namespace ConsoleApplication1 {
    class Program {
        static void Main(string[] args) {
            Regex reg = new Regex("[A-Z][a-z]*[0-9]*");
            String str = "C23H24Na1O";

            StringBuilder sb = new StringBuilder();
            foreach (Match m in reg.Matches(str)) {
                sb.Append(m.Value);
                if (Char.IsDigit(m.Value[m.Value.Length - 1]) == false) {
                    sb.Append(1);
                }
            }

            Console.WriteLine(sb.ToString());
            Console.ReadLine();
        }
    }
}

This shows how to use a Regular expression to break your string into parts then check each part for the number condition. Line 8 says "I need 1 capital letter, followed by optional (the *) lower case letters followed by optional numbers". Line 14 checks if the last character in each section is a number, and if not add "1" to our string.

[srikanth2321]

Hi Momerath,

Thanks a lot.

[Momerath]

Please mark this thread solved if it is :)