Letter replacement in string

Question

I have this simple code for letter substitution. What I would like to add is, that if i.e., I replace letter A with letter T, all T letters are automatically replaced with A as well. So if I have a word "atatatat", the following code changes the word to "tttttttt", but it should change it to "tatatata". How can I fix this?

private void button3_Click(object sender, EventArgs e) { String key= this.textBox1.Text; String letter1 = this.textBox2.Text; String letter2 = this.textBox3.Text; StringBuilder newKey = new StringBuilder(); newKey.AppendLine(key); newKey.Replace(letter1, letter2); this.textBox4.Text = noviKljuc.ToString(); }

I tried with adding this line: newKey.Replace(letter2, letter1); But this changes word to "aaaaaaaa"

joce · Accepted Answer · 2013-03-17 19:25:58Z

5

Just iterate through letters and change them one by one:

foreach(char c in key){ if(c==letter1){ newKey.Append(letter2); }else if(c==letter2){ newKey.Append(letter1); }else{ newKey.Append(c); } }

edited Mar 17, 2013 at 19:25

joce

9,92019 gold badges58 silver badges75 bronze badges

answered Mar 17, 2013 at 19:22

alex

12.7k4 gold badges50 silver badges69 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

cvenko Over a year ago

Tried it, but it returns the same word as the one provided at start. No idea how tho.

alex Over a year ago

Try replacing String letter1 = this.textBox2.Text; with char letter1=this.textBox2.Text[0]; . Same for letter2.

joce Over a year ago

This will do a replacement of the 2nd letter even if the 1st one isn't found.

joce · Accepted Answer · 2013-03-17 19:42:39Z

You need to iterate over each letter, detect if you proceed with the change, and then do the second replacement only if the first one took place:

// Check to see if we can find the 1st char to replace in the string bool doReplace = key.Any(c => c == originalChar); if (doReplace) { foreach (char c in key) { if (c == originalChar) { newKey.Append(alternateChar); } else if (c == alternateChar) { newKey.Append(originalChar); } else { newKey.Append(c); } } } else { newKey = key; } this.textBox4.Text = newKey.ToString();

the_joric · Accepted Answer · 2013-03-17 19:55:24Z

try this one

var result = String.Join("", key.Select(c => c == letter2 ? letter1 : c == letter1 ? letter2 : c ));

Collectives™ on Stack Overflow

Letter replacement in string

3 Answers 3

3 Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

Comments

Related