How do I return a string when another string isn't found in txt file?

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I'm so close with this but the last section of this is driving me insane. I have a txt file that is read by this code, and if it fails to find the string in the file, I want it to return a string once saying "string not found".

However the current code (below) returns "string not found" for each line the string isn't found, which is not what I'm after. I want it to read through the whole document and return it once when the string isn't found. Any ideas?

C#

int counter = 0;
string dt;

StreamReader file = new StreamReader(path);

while ((dt = file.ReadLine()) != null)
{
    if (dt.Contains(thisLetter))
    {
        thisType = dt;
    }
    else
    {
		Console.WriteLine("string not found");
		// Returns for every single line of the file that doesn't contain string. Which is not what I'm after.
		// Want it to return once on not finding string in file.
    }
    counter++;
	
file.Close();

What I have tried:

Have tried adding in addition code to check document for the string but it does not have the desired effect the ways I've done it.

Posted 5-May-22 3:04am

Member 14740628

Updated 5-May-22 4:10am

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Comments

Graeme_Grant 5-May-22 9:31am

[moved]

[no name] 5-May-22 9:55am

[removed spam]

3 solutions

Solution 1

"I want it to return a string once saying "string not found""

The check then should be outside the loop after you finish reading.

Posted 5-May-22 3:33am

Graeme_Grant

Solution 3

The simplest solution is this:

string dt;

using (StreamReader file = new StreamReader(path))
   {
   while ((dt = file.ReadLine()) != null)
      {
      if (dt.Contains(thisLetter))
         {
         thisType = dt;
         return;
         }
      }
   Console.WriteLine("string not found");
   }

Posted 5-May-22 4:10am

OriginalGriff

Comments

Rajeev Jayaram 5-May-22 10:15am

Good one!

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Rajeev Jayaram · Accepted Answer · 2022-05-05T04:06:00

Solution using a bool variable,

int counter = 0;
string dt;
bool isFound = false;

StreamReader file = new StreamReader(path);

while ((dt = file.ReadLine()) != null)
{
    if (dt.Contains(thisLetter))
    {
        isFound = true;
        thisType = dt;
    }
    counter++;
}
if(!isFound)
{
    Console.WriteLine("string not found");
}
file.Close();