Learning C#

Variables

A variable is an object that can hold a value:

int myVariable = 15;

You initialize a variable by writing its type, its identifier, and then assigning a value to that variable. The previous section explained types. In this example, the variable’s type is int (which is, as you’ve seen, a type of integer).

An identifier is just an arbitrary name you assign to a variable, method, class, or other element. In this case, the variable’s identifier is myVariable.

You can define variables without initializing them:

int myVariable;

You can then assign a value to myVariable later in your program:

int myVariable;
// some other code here
myVariable = 15;  // assign 15 to myVariable

You can also change the value of a variable later in the program. That is why they’re called variables; their values vary.

int myVariable;
// some other code here
myVariable = 15;  // assign 15 to myVariable
// some other code here
myVariable = 12;  // now it is 12

Technically, a variable is a named storage location (i.e., stored in memory) with a type. After the final line of code in the previous example, the value 12 is stored in the named location myVariable.

WriteLine( )

The .NET Framework provides a useful method for displaying output on the screen in console applications: System.Console.WriteLine( ). How you use this method will become clearer as you progress through the book, but the fundamentals are straightforward. You call the method, passing in a string that you want printed to the console (the ...