C# Programming/Syntax
C# syntax looks quite similar to the syntax of Java because both inherit much of their syntax from C and C++. The object-oriented nature of C# requires the high-level structure of a C# program to be defined in terms of classes, whose detailed behaviors are defined by their statements.
Statements
[edit | edit source]The basic unit of execution in a C# program is the statement. A statement can declare a variable, define an expression, perform a simple action by calling a method, control the flow of execution of other statements, create an object, or assign a value to a variable, property, or field. Statements are usually terminated by a semicolon.
Statements can follow in sequence or be grouped in brace-enclosed statement blocks.
Examples:
int sampleVariable; // declaring a variable sampleVariable = 5; // assigning a value Method(); // calling an instance method SampleClass sampleObject = new SampleClass(); // creating a new instance of a class sampleObject.ObjectMethod(); // calling a member function of an object // executing a "for" loop with an embedded "if" statement for (int i = 0; i < upperLimit; i++) { if (SampleClass.SampleStaticMethodReturningBoolean(i)) { sum += sampleObject.SampleMethodReturningInteger(i); } } Statement blocks
[edit | edit source]A series of statements surrounded by curly braces form a block of code. Among other purposes, code blocks serve to limit scope, or the range in which a variable can be used. A variable is only accessible in the block in which it is defined. Code blocks can be nested and often appear as the bodies of methods.
private void MyMethod(int integerValue) { // This block of code is the body of "MyMethod()" // The 'integerValue' integer parameter is accessible to everything in the method int methodLevelVariable; // This variable is accessible to everything in the method if (integerValue == 2) { // methodLevelVariable is still accessible here int limitedVariable; // This variable is only accessible to code in the, if block DoSomeWork(limitedVariable); } // limitedVariable is no longer accessible here } // Here ends the code block for the body of "MyMethod()". Comments
[edit | edit source]Comments allow inline documentation of source code. The C# compiler ignores comments. These styles of comments are allowed in C#:
- Single-line comments
- The
//character sequence marks the following text as a single-line comment. Single-line comments, as one would expect, end at the first end-of-line following the//comment marker. - Multiple-line comments
- Comments can span multiple lines by using the multiple-line comment style. Such comments start with
/*and end with*/. The text between those multi-line comment markers is the comment.
// This style of a comment is restricted to one line. /* This is another style of a comment. It allows multiple lines. */ - XML Documentation-line comments
- These comments are used to generate XML documentation. Single-line and multiple-line styles can be used. The single-line style, where each line of the comment begins with
///, is more common than the multiple-line style delimited by/**and*/.
/// <summary> documentation here </summary> /// <remarks> /// This uses single-line style XML Documentation comments. /// </remarks> /** * <summary> documentation here </summary> * <remarks> * This uses multiple-line style XML Documentation comments. * </remarks> */ Case sensitivity
[edit | edit source]C# is case-sensitive, including its variable and method names.
The variables myInteger and MyInteger of type int below are distinct because C# is case-sensitive:
int myInteger = 3; int MyInteger = 5; For example, C# defines a class Console to handle most operations with the console window. Writing the following code would result in a compiler error unless an object named console had been previously defined.
// Compiler error! console.writeline("Hello"); The following corrected code compiles as expected because it uses the correct case:
Console.WriteLine("Hello");