Determining Whether a String Is a Valid Number

Determining Whether a String Is a Valid Number

Problem

You have a string that possibly contains a numeric value. You need to know whether this string contains a valid number.

Solution

Use the static TryParse method of any of the numeric types. For example, to determine whether a string contains a double, use the following method:

	    string str = "12.5";
	    double result = 0;
	    if(double.TryParse(str,
	            System.Globalization.NumberStyles.Float,
	            System.Globalization.NumberFormatInfo.CurrentInfo,
	            out result))
	    {

	        // Is a double!
	    }

Discussion

This recipe shows how to determine whether a string contains only a numeric value. The tryParse method returns true if the string contains a valid number without the exception that you will get if you use the Parse method. Since TRyParse does not throw exceptions, it performs better over time given a set of strings where some do not contain numbers.

See Also

See the "Parse" and "TryParse" topics in the MSDN documentation.