. NET C # language Fundamentals 20140814

One. NET history

1.. The History of Net

Web--HTML--asp/asp.net--ASPX--. NET

DOS black screen static page dynamic page--Unlimited expansion of database ASP 2002

2.. NET software updates

Second, C # programming

1. Project structure

. cs--program code files, source files

. config--configuration file

. csproj--project file (used to manage file entries)

. sln--solution files (for managing projects)

PS: After the selection is removed, only the item is removed, and the item still exists in the file.

2. Functions

Definition: Ability to perform a function independently

Four elements: 1) Name 2) input 3) output 4) processing

Main function: static void Main (string [] args)
{
}

Input statement:

string s = Console.ReadLine ();

Output statement:

Console.WriteLine ("What to Output");(display content wrapping, cursor on second line)

Console.Write ("What to Output");(display does not wrap, the cursor is behind the input)

Ps:main "M" must be uppercase, statement ends with ";".

Shortcut keys:

Delete entire line: Shift+del

Check change to comment: Ctrl+k+c Cancel: Ctrl+k+u

(Note: "//", "*/*".)

AutoCorrect for Words: ALT + "→" (rightwards Arrow)

3. Data type

1) integral type: int short long byte

2) Float type: float double decimal

3) Character type: Char

4) Boolean type: BOOL

5) string-type: string

6) DateTime Date/Time type

Ps:char with "display content, string with" "" display content; Common data type: Int (integer), double (floating point type).

4. Variables

1) Naming rules for variables:

A. Consists of letters, numbers, underscores, symbols @, Chinese characters.

B. The first character cannot be a number.

C. The name cannot be the same as the System keyword.

Example: an illegal identifier

a.2x--first letter cannot be a number

b.class--and System "class" duplicate name

c.c#+variable--"#" "+" for illegal symbols

2) Definition of variables

Data type variable name [= value];

int a = 10;

3) Use of variables: assignment, value

A = 90;

A = a + 100;

The floating-point type defaults to double, and if you want to use float, you can use the "F" suffix.

Example: Fioat a=8.2f

5. Constants
1) Classification:

A. Symbolic constants: replacing values with symbols

B. Literal constants: The value to the right of "="

2) Definition of Symbolic constants: Add "const" before variable definition

Example: const BOOL D=true

3) Use of symbolic constants: cannot be assigned, only values can be taken.

4) Escape character

' \a '--sound

' \ t '--tab key character

' \ \ '--backslash-appears as ' \ '

' \ '--single quote

' \ '--double quotes

' \ n '--wrap

' \ R '--Enter

Example: Console.WriteLine ("Zhang San said: \" Are you a person? ")

Show as Zhang San said: "Are you a person?"