How to check if string contains the text in C# Winforms

Question

Can anyone help me in writing a piece of code in C# Winforms, which can give me a boolean value, that whether a piece of string contains a few words.

For example, If I want to check whether string test only string exists in string "Data is provided to test only string".

I have written following piece of code, but it alwys gives me true, whether string contains the words or nor.

    private bool ContainsText(string input)
    {
        for (int i = 0; i < input.Length; i++)
        {
            if (((int)input[i] >= 65 && (int)input[i] <= 90) || ((int)input[i] >= 97 && (int)input[i] <= 177))
                return true;
        }

        return false;
    }

When I call the following line, I always get true, which is not correct

MessageBox.Show(ContainsText("test only string").ToString());

There's a String.Contains method ya know...

It'sNotALie.
– It'sNotALie.

2013-03-16 17:59:47 +00:00
Commented Mar 16, 2013 at 17:59 — It'sNotALie.
– It'sNotALie., Commented Mar 16, 2013 at 17:59

Jon Skeet · Accepted Answer · 2013-03-16 18:02:32Z

Code-wise, your ContainsText code immediately returns true if any character in input is either in "A to Z" or "a to U+00B1" for some reason.

But the problems lie deeper than that: you've described two inputs - the string to check for, e.g. "test only string" and the string to check for its presence, e.g. "Data is provided to test only string". Your method only accepts one input, and doesn't use any other state. So it can't possibly work. It's worth taking a step back and trying to work out why you didn't notice that you needed two inputs - and why indeed your test only used "test only string" and didn't mention "Data is provided to test only string".

You don't really need a method at all though - String already has a Contains method:

if (textToCheck.Contains(textToFind))
{
    ...
}

That's assuming you want an ordinal comparison. Use IndexOf with an appropriate StringComparison if you want to check in a culture-sensitive or case-insensitive way.

nsconnector · Accepted Answer · 2013-03-16 18:01:49Z

1

You can use Contains method of String object.

var a = "Data is provided to test only string";
var b = "test only string";

if (a.Contains(b))
     MessageBox.Show("yes");

answered Mar 16, 2013 at 18:01

nsconnector

8366 silver badges12 bronze badges

Comments

Steve · Accepted Answer · 2013-03-16 18:06:44Z

1

A simple string.IndexOf perhaps with the enum to ignore case:

 string myTestString = "Data is provided to Test Only String";
 if(myTestString.IndexOf("test only string", StringComparison.CurrentCultureIgnoreCase) >= 0)
    Console.WriteLine("Found text");

Of course the string class has also a Contains method, but it is implemented as a call to IndexOf, without the possibility to ignore the case.

public bool Contains(string value)
{
     return (this.IndexOf(value, StringComparison.Ordinal) >= 0);
}

edited Mar 16, 2013 at 18:06

answered Mar 16, 2013 at 18:01

Steve

217k22 gold badges242 silver badges296 bronze badges

Comments

Sam · Accepted Answer · 2013-03-16 18:26:21Z

0

Use IndexOf

http://www.dotnetperls.com/indexof

example of usage..

string str = "string to test";
bool result = str.IndexOf("The hosted network started.") != -1;

MessageBox.Show(result.ToString());

edited Mar 16, 2013 at 18:26

answered Mar 16, 2013 at 18:00

Sam

7,3333 gold badges27 silver badges37 bronze badges

Collectives™ on Stack Overflow

How to check if string contains the text in C# Winforms

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related