First, C # basic syntax
1. Annotation characters
- Single-line Comment: Add "//" in front of the code or text you want to comment
- Multiline Comment:/* What you want to comment */
- Document Comment: Press three consecutive "/" on the previous line of the method or class to OK
- Role: A. Write-off of unused code
B. Explain the code that was written
Key shortcuts used in 2.VS
- Ctrl+k+d: Quickly align the Code of this page
- Ctrl+j: Pop Up Smart Tips
- Ctrl+k+c: Note the selected code
- Ctrl+k+u: Cancels the comment for the selected code
- F1: Jump to help document
- #Region, #EndRegion: Folding redundant code
3. Variables: Used to store data in a computer
- Requirements for defining variables: A. To determine the stored data type
B. To give the storage space a meaningful name, convenient for us to use later
- Syntax: A. Variable type variable name; Variable name = value;
B. Variable type variable name = value;
- Usage rules: Declare first, then assign value, use after
- Note: The variable for a string can be empty, but the character variable cannot be empty
4. Naming rules
- Camel case: The first letter of the first word is lowercase, the first letter of each of the remaining words is capitalized; for local variables and method parameters
- Pascal case: Capitalize the first letter of each word; for type name and member name
- All caps: Uppercase as the name implies; used for abbreviations
5. Use of the "+" sign
- String connection (on both sides of the "+" sign if one side is a string type)
- Numbers are added (when the "+" sign is both numeric types)
6. Use of placeholders: dig holes first, then pits
- The hole-digging index is starting from 0.
- Dig n a hole to fill N a pit (more fill, no effect; less fill, throw exception)
- The order of the outputs is output in the order in which the pits are dug.
* Exception (Exception): In the process of running the program, for some reason the problem, so that the program does not work properly (commonly known as bug)
* error: Refers to a problem with code syntax that causes program compilation to not complete
7. Swap variables
- Use third-party variables ()
- Do not use third-party variables (interview written questions, and only apply to numeric types)
8. Type Conversion
- Explicit conversions (Large range → small range) require write-code conversion
A.convert.toint32 parameters are more, Int.parse can only convert a string of type
B.parse is to convert string into int,char,double .... And so on, that is *. Parse (string) must be a string in parentheses
C.convert can provide multiple types of conversions, that is, convert.* () can be of many types (including string) in parentheses
- Implicit conversion (small range → wide range) auto-conversion without writing code
[email protected] The role of the symbol
- Eliminate the escape effect of ' \ ' in a string
- Output a string in the original format of the edit
10. Common Escape characters
- \ n : Line Break
- \ ": Displays double quotation marks in English half-width
- \t:tab the space of the key
- \b: Backspace (no effect on both sides of the string)
- \ \: Displayed as a ' \ '
Wen Xin (i)
