Casting Y or N to bool C#

Question

Just for neatness sake I was wondering, whether it\'s possible to cast Y or N to a bool? Something like this;

bool theanswer = Convert.ToBoolean(input);
         


        

Answer 1

No, there's nothing built in for this.

However, given that you want to default to false, you can just use:

bool theAnswer = (input == "y");

(The bracketing there is just for clarity.)

You may want to consider making it case-insensitive though, given the difference between the text of your question and the code you've got. One way of doing this:

bool theAnswer = "y".Equals(input, StringComparison.OrdinalIgnoreCase);

Note that using the specified string comparison avoids creating a new string, and means you don't need to worry about cultural issues... unless you want to perform a culture-sensitive comparison, of course. Also note that I've put the literal as the "target" of the method call to avoid NullReferenceException being thrown when input is null.

Answer 2

how about this.

bool theanswer = input.Equals("Y", StringComparison.OrdinalIgnoreCase);

or yet safer version.

bool theanswer = "Y".Equals(input, StringComparison.OrdinalIgnoreCase);

Answer 3

Or this?

bool CastToBoolean(string input)
{
    return input.Equals("Y", StringComparison.OrdinalIgnoreCase);
}

Answer 4

Create a extension method for string that does something similar to what you specify in the second algorithm, thus cleaning up your code:

public static bool ToBool(this string input)
{
    // input will never be null, as you cannot call a method on a null object
    if (input.Equals("y", StringComparison.OrdinalIgnoreCase))
    {
         return true;
    }
    else if (input.Equals("n", StringComparison.OrdinalIgnoreCase))
    {
         return false;
    }
    else
    {
         throw new Exception("The data is not in the correct format.");
    }
}

and call the code:

if (aString.ToBool())
{
     // do something
}

Answer 5

I faced the same problem but solved other way.

bool b=true; 
        decimal dec; 
        string CurLine = "";        
        CurLine = sr.ReadLine();
        string[] splitArray = CurLine.Split(new Char[] { '=' });
        splitArray[1] = splitArray[1].Trim();
        if (splitArray[1].Equals("Y") || splitArray[1].Equals("y")) b = true; else b = false;
        CurChADetails.DesignedProfileRawDataDsty1.Commen.IsPad = b;

Answer 6

DotNetPerls has a handy class for parsing various string bools.

/// <summary>
/// Parse strings into true or false bools using relaxed parsing rules
/// </summary>
public static class BoolParser
{
    /// <summary>
    /// Get the boolean value for this string
    /// </summary>
    public static bool GetValue(string value)
    {
       return IsTrue(value);
    }

    /// <summary>
    /// Determine whether the string is not True
    /// </summary>
    public static bool IsFalse(string value)
    {
       return !IsTrue(value);
    }

    /// <summary>
    /// Determine whether the string is equal to True
    /// </summary>
    public static bool IsTrue(string value)
    {
       try
       {
            // 1
            // Avoid exceptions
            if (value == null)
            {
                return false;
            }

            // 2
            // Remove whitespace from string
            value = value.Trim();

            // 3
            // Lowercase the string
            value = value.ToLower();

            // 4
            // Check for word true
            if (value == "true")
            {
                return true;
            }

            // 5
            // Check for letter true
            if (value == "t")
            {
                return true;
            }

            // 6
            // Check for one
            if (value == "1")
            {
                return true;
            }

            // 7
            // Check for word yes
            if (value == "yes")
            {
                return true;
            }

            // 8
            // Check for letter yes
            if (value == "y")
            {
                return true;
            }

            // 9
            // It is false
            return false;
        }
        catch
        {
            return false;
        }
    }
}

Is called by;

BoolParser.GetValue("true")
BoolParser.GetValue("1")
BoolParser.GetValue("0")

This could probably be further improved by adding a parameter overload to accept an object.