What does this symbol mean in C, it is used before creating the folder

Match is used in front of a string to indicate that this is a string, of course, it should be used before double quotation marks.

Strings are of type string and can be written in two forms, enclosing them in quotation marks and enclosing them in @. Strings enclosed in quotation marks are enclosed in double quotation marks (") within:

The advantage of using @ is that the transcoding sequence is "not" handled, so that the string can be easily written.

For example: @"c:\docs\source\"Or written"c:\\docs\\source\\"

Simply say @" ..", in C is a literal string, for example, for the purpose of representing the Windows path

c:\windows\temp

Such a path in C should be represented like this:

string path = "c:\\windows\\temp";

The number of occurrences can be really dizzying at times

You use @, and that's it.

string path = @"c:\windows\temp";

It can also be used in query data to prevent SQL character injection!

Damn, this is the content of a book, can you do it in one sentence here? Read the book and go!

Khan: There are so many symbols you said, go figure it out for yourself and read the book

r is to open the file in read-only mode.

w is to open the file in write-only mode.

R+ is open for read/write mode.

w+ is open for read/write mode.

Add b to open in binary mode.

r:read, read the file.

w: write, write the file.

w+, r+: read and write files.

rb, wb, wb+, rb+: perform operations on binaries.

The portable dry powder fire extinguisher has the characteristics of simple structure, flexible operation, easy to use, fast fire extinguishing speed, high efficiency, continuous or intermittent spraying, etc.

Scope of application of fire extinguisher: Class A extinguishes ordinary solid material fires. Class B extinguishes a liquid fire. Class C extinguishing gas and steam fires. Fire involves electrified electrical equipment.

It is an ideal fire extinguishing equipment for factories, institutions, schools, hotels and all kinds of vehicles. Portable ABC dry powder fire extinguisher series products are small fire extinguishing equipment with novel structure, high fire extinguishing efficiency, simple operation and easy to carry, which has the advantages of non-toxic, non-corrosive and easy to clean up the rescued items after use.

The specific steps are as follows: view - > header and footer (pop up header and footer box) - > insert "from ** anthology" - > page x of y pages.

Create a new one for me. doc. Create a 2x2 ** in this file.

The first line "China", "China". Line 2: "United States", "american". Save to close My Index.

Open by clicking Insert --References--Index & Table of Contents. Select auto-tagging in the index to turn on My Index off. Then click Insert --References--Index & Table of Contents.

Don't select any selections, click OK to save. Save my All operations are done.

Level 1 priority.

Parenthesis. Subscript operator.

Point to the struct member operator.

Struct member operator.

Level 2 priority.

Logical non-operators.

Bitwise negation operator.

Autoincrement operator.

Self-decrement operator.

Negative operator.

Type) type conversion operator.

Pointer operator.

Addresses and operators.

sizeof length operator.

Level 3 priority.

Multiplication operators.

Division operator.

Remainder operator.

4 levels of priority.

Addition operators.

Subtraction operators.

5 levels of priority.

Shift Left operator.

Shift right operator.

6 levels of priority.

<=, >, = relational operators.

7 levels of priority.

Equals operator.

Not equal to the operator.

8 levels of priority.

Bitwise and operators.

9 levels of priority.

Bitwise or operator.

10 levels of priority.

Bitwise XOR operators.

11 levels of priority.

Logic and operators.

12 levels of priority.

Logic or operators.

13 levels of priority.

Conditional operators.

14 levels of priority.

The above are assignment operators.

15 levels of priority.

Comma operator.

15 levels in total, done.

Hand-copied Wuhan University C language programming.

1.Chinese core journals are what we usually call core journals, which are included in the "Overview of Chinese Core Journals" published by Peking University, which is published every 4 years, and now uses the 2008 edition.

2.Founded in 1989, Chinese Science Citation Database (CSCD) has been a series of databases for scientific bibliometric evaluation in China since 1999, jointly sponsored by the Library and Information Center of the Chinese Academy of Sciences and the Electronic Journal of Chinese Academic Journals (CD-ROM Edition), and officially published by Tsinghua Tongfang CD-ROM Electronic Publishing House.

1.Chinese core journals are what we usually call core journals, which are published by the "Overview of Chinese Core Journals" co-edited by Peking University Library and Beijing University Library Journal Work Research Association and published by Peking University Press, which is updated and published every 4 years.

2.China's core journals of science and technology are published by the Ministry of Science and Technology, that is, "China Science and Technology ** Statistical Source Journal", sometimes we can see a magazine marked with China Science and Technology Core Journal, China Science and Technology ** Statistical Source Journal, Chinese Core Journal (or Chinese Medicine and Health Core Journal), in fact, the first two are no difference.

3.CSCD core journals: CSCD is the English abbreviation of China Science Citation Database, CSCD is searched in university applications** and review awards, including the review of academicians; CSCD is divided into core library (C) and extended library (E), with the core library having a slightly higher magazine grade (relatively speaking).

For example, the Journal of the Third Military Medical University is not only a core journal of CSCD, but also a statistical source journal of China's science and technology.

Journal of Chongqing Medical University is a Chinese core, Chinese science and technology core, cscd selection and excellent scientific and technological journal of Chinese universities.