从文本中删除全部3个相同的词

Question

I want to delete 3 words called "apple" from a string of textbox. Textbox contain more than 3 apple words. I need to select only 3 to delete.

I used this code but it delete all apple words from the string.

private void button4_Click(object sender, EventArgs e)
{
    textBox3.Text = textBox3.Text.Replace("apple","");
}

I want to delete 3 words only. Do you have any idea how to achieve this?

Answer 1

You could use the overload of Regex.Replace to specify the maximum number of times to replace

var regex = new Regex("apple");
var newText = regex.Replace(textBox3.Text, "", 3);

Answer 2

Yet another possibility is to Split (treating "apple" as a separator ) and Concat back:

// 3 + 1: we want 3 separators to be eliminated, and thus 4 = 3 + 1 parts 
textBox3.Text = string.Concat(textBox3.Text
  .Split(new string[] { "apple" }, 3 + 1, StringSplitOptions.None));

Answer 3

You could try to look for the word "apple" three times (or less if it doesn't appear three times) in your string and to remove it from your current string.

private void button4_Click(object sender, EventArgs e)
{
    const string stringToRemove = "apple";

    int i = 0;
    int index = 0;
    string textBoxString = textBox3.Text;

    while(i<3 && index >= 0)
    {
        index = textBoxString.IndexOf(stringToRemove);

        textBoxString = (index < 0)? textBoxString : textBoxString.Remove(index, stringToRemove.Length);
        i++;
    }

    textBox3.Text = textBoxString;
}

Answer 4

There`s multiple way to accomplish what you want. 1 of is is using regex, and 1 of is as sample below, basically loop and replace on how many time u want it to be.

string value = textBox3.Text;
for(int a = 0; a < 2;a++){
value = value.replace("apple","");
}

textBox3.Text=value;