<?xml version="1.0"?> <clause number="14.5.11" title="The typeof operator"> <paragraph>The typeof operator is used to obtain the System.Type object for a type. <grammar_production><name><non_terminal where="14.5.11">typeof-expression</non_terminal></name> : <rhs><keyword>typeof</keyword><terminal>(</terminal><non_terminal where="11">type</non_terminal><terminal>)</terminal></rhs><rhs><keyword>typeof</keyword><terminal>(</terminal><keyword>void</keyword><terminal>)</terminal></rhs></grammar_production></paragraph> <paragraph>The first form of <non_terminal where="14.5.11">typeof-expression</non_terminal> consists of a typeof keyword followed by a parenthesized type. The result of an expression of this form is the System.Type object for the indicated type. There is only one System.Type object for any given type. <note>[Note: This means that for type T, typeof(T) == typeof(T) is always true. end note]</note> </paragraph> <paragraph>The second form of <non_terminal where="14.5.11">typeof-expression</non_terminal> consists of a typeof keyword followed by a parenthesized <keyword>void</keyword> keyword. The result of an expression of this form is the System.Type object that represents the absence of a type. The type object returned by typeof(<keyword>void</keyword>) is distinct from the type object returned for any type. </paragraph> <paragraph> <note>[Note: This special type object is useful in class libraries that allow reflection onto methods in the language, where those methods wish to have a way to represent the return type of any method, including <keyword>void</keyword> methods, with an instance of System.Type. end note]</note> </paragraph> <paragraph> <example>[Example: The example <code_example><![CDATA[ using System; class Test { static void Main() { Type[] t = { typeof(int), typeof(System.Int32), typeof(string), typeof(double[]), typeof(void) }; for (int i = 0; i < t.Length; i++) { Console.WriteLine(t[i].FullName); } } } ]]></code_example>produces the following output: <code_example><![CDATA[ System.Int32 System.Int32 System.String System.Double[] System.Void ]]></code_example></example> </paragraph> <paragraph> <example>Note that <keyword>int</keyword> and System.Int32 are the same type. end example]</example> </paragraph> </clause>