Difference between revisions of "Csharp programming syntax"

Revision as of 20:39, 23 December 2010

What follows is a basic look at the C# programming language.

C# is a strongly typed language. That means that the variable type matters. You cannot assign a variable of one type to another of a different type without performing a type cast. C# is compiled into IL code that is then compiled just in time by the .NET framework. The .NET framework handles things like program execution and memory management. As a result C# is considered "managed code." C# is case sensitive so Var1 is different from var1.

Basic Syntax

White Space and Comments

C# uses the ; to terminate statements. As a result statements can have whitespace formatting characters(tabs, line feeds, carriage returns, etc.).

Example:

 CallSomeFunction(param1, param2, param3);

is the same as:

 
 CallSomefunction(param1,
 :param2,
 :param3);

Variable Declaration

//value types can be initialized upon instantiation
[scope] Type name = value;

//reference types can be initialized up instantiation
[scope] Type name = new Type(contructor params);

//or not
[scope] Type name = null;

Value Type Example:

 private int myInt = 0;

Reference Type Example:

 private string myNewString = "fred";
 string myNewString = null;
 SomeObject myObject = new SomeObject(Param1);
 SomeObject myOtherObject = null;

Operators

Assignment Operator: = example: this.Text = "fred"; will assign the name fred to the form caption
Equality Operator: == example: if(this.Text == "fred")do something here;
OR Operator: || example: if(this || that) -- read as: if this OR that then
AND Operator: && example: if(this && that) -- read as: if this AND that then
Addition: + example: 1+1 = 2
Subtraction: - example: 1-1 = 0
Multiplication: * example: 2*1 = 2
Division: / example: 10/2=5
Add to existing: += example: x += y is equivalent to x = x + y
Subtract from existing: -= example: x -= y is equivalent to x = x - y

Conditional Execution

The If Statement

//the if statement<br>
if(a == a)<br>
{
 //do something;
 ....
}
else if(a == b)
{
 //do something else;
 ....
}
else 
{
 //nothing else evaluates to true so do this;
 ....
}
 
//simplified
if(1==1)
SingleStatementToExecute;
else
SomethingElse;

The Switch Statement

The switch statement is there to help you avoid writing complex else if() statements.

//the switch statement
switch(SomeVar)
{
 case someConstant: doStuffHere; //same as if(SomeVar == someConstant)then
 break;
 
 case someOtherConstant: doOtherStuffHere; //same as if(SomeVar == someOtherConstant)then
 break;
 
 default:
 break;
}