<< Dark Horse programmer >> Keywords, identifiers and annotations for C language

Keywords for C language

A total of 32 keywords are available in the C language :

Features: ①c language keywords are all lowercase letters.

② keywords in the development tool or Smart text Editing tool will display a special color font, by default, the C keyword in Xcode will show the purple-brown.

The key words of C language are: int, return.

C-language identifiers

1 What are identifiers

C language identifier is in the program to customize some of the symbols and names, to be separated from our keywords, the keyword is the C language provided by the symbol, the identifier is the programmer's own definition.

2 naming rules for identifiers (must be followed)

① can only be composed of 26 English letters, 10 Arabic numerals and underscores;

② are strictly case-sensitive, such as test and test are two different identifiers;

③ cannot begin with a number;

④ can not use keywords as identifiers;

3 Naming conventions for identifiers

① try to make a meaningful name for the identifier, you can use an English word, or you can use pinyin.

② If there are more than one word in the identifier, you can use the hump flag to capitalize the first letter of each word except for the first letter.

Comments

1 What is a comment

Annotations are important in a program, and annotations can explain the meaning of a program and a line of code, which can be any word, number, or word.

2 Single-line comment

① adds two to the front of each line of comments//To comment all explanations behind the slash.

② can write notes anywhere.

3 Multi-line comments

Multiline comments start with/*, end with */, the contents of/* and/* are commented

4 Nested behavior of annotations.

① Single-line comments can nest single-line comments, multiline comments .

② Multiline comments can nest single-line comments .

③ Multiline comments cannot nest multiple lines of comments .

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