I'm trying to find a way to count the number of chars in a certain word starting with a certain char from a given string in c# using only system.

So for example for the following string "the weather outside is beautiful". If I want to count the number of chars for the word "outside" using as a rule just the first letter (in this case will be "o"), can I count somehow the number of chars preceding the o? (in this case will be 6).

I was thinking that it should be something like:

If word starts with "o" than count the following chars and stop counting when we find space, return number.

I tried finding something similar but unfortunately I wasn't successful.

As an addition, there will be only one word starting with the letter o. (or another letter which will be used as a finding rule)

I hope the question is clear enough and thank you in advance!

CodePudding user response：

Perhaps use Regex:

var text = "the weather outside is beautiful";
var regex = new Regex(@"(o.*?)\b");
var length = regex.Match(text).Captures[0].Length;
Console.WriteLine(length);

That gives 7.

CodePudding user response：

The general approach would be to

• Split() string by spaces: you get a list of words
• iterate list and check first letter of each word
• if word starts with 'o': get the lenght of word

you can do this either using String.Split() - leveraging System.Linq, or even by using simple loops.

Using loops:

public class Program
{
    public static void Main()
    {
        var text = "the weather outside is beautiful";
        
        var word = "";
        foreach( var l in text)
        {
            if (word == "" && l == 'o')
            {
                word  = l;
            } 
            else if (word != ""  && l == ' ')
            {
                System.Console.WriteLine(string.Format("{0} : {1}",
                                         word, word.Length));
                word = "";
            }
            else if (word != "")
            {
                word  = l;
            }
        }
    }
}

This (and the others) output:

outside : 7

Using String.Split():

public class Program
{
    public static void Main()
    {
        var text = "the weather outside is beautiful";

        var words = text.Split(' ');
        
        foreach( var w in words)
        {
            if (w.StartsWith("o"))
                System.Console.WriteLine(string.Format("{0} : {1}",
                                         w, w.Length));
        }
    }
}

Using Linq:

using System;
using System.Linq;

public class Program
{
    public static void Main()
    {
        var text = "the weather outside is beautiful";
        
        var splitted = text
            .Split(' ')
            .Where(w => w.StartsWith("o", StringComparison.OrdinalIgnoreCase));
        
        foreach(var w in splitted)
            System.Console.WriteLine(string.Format("{0} : {1}", w, w.Length));      
    }
}