Other Topics - Illustrated C# 2005 - page 523

Parsing Strings to Data Values
Strings are arrays of Unicode characters. For example, string "25.873" is six characters long
and is not a number. Although it looks like a number, you cannot perform arithmetic functions
on it. “Adding” two strings produces a concatenation of them.

￿ Parsing allows you to take a string that represents a value and convert it into an actual

numeric value.

All the predefined, simple types have a static method called Parse , which takes a string
value representing the type and converts it into an actual value of the type.

￿

The following statement shows an example of the syntax of using a Parse method. Notice
that Parse is static, so you need to invoke it by using the name of the target type.

double d1 = double.Parse("25.873");
↑ ↑
Target type String to be converted

The following code shows an example of parsing two strings to values of type double and
then adding them.

static void Main()
{
string s1 = "25.873";
string s2 = "36.240";

double d1 = double.Parse(s1);
double d2 = double.Parse(s2);

double total = d1 + d2;
Console.WriteLine("Total: {0}", total);
}

This code produces the following output:

Total: 62.113

If the string cannot be parsed, the system raises an exception. There is another static
method, TryParse , which returns true if the string was successfully parsed, and false other-
wise. It does not raise an exception if the parse fails.

■ Note A common confusion about Parse is that, since it operates on a string, it is often thought of as a
member of the string class. It is not. Parse is not a single method at all, but a number of methods imple-
mented by the target types.