Basic syntax of C programming

You already know about the basic structure of the C program, now you will easily understand the basic blocks in the C language.

The Token in C

In C language, there are many different tokens and a token can be a keyword, an identifier, a constant, a string or a character. For example, the following C command line includes the following 5 tokens:

 printf ( "Hello, World! n" ); 

Separate tokens are as follows:

 printf ( "Hello, World! n" ) ; 

Semi-colon ; in C

Program C, semicolon is part of the command end. In fact, each command in C must end with a semicolon. It informs the end of a logical attribute.

The following example is 2 commands:

 printf ( "Hello, World! n" ); return 0 ; 

Comment in C

The comment is the same as the help in C program and is ignored by the compiler. It starts with / * and ends with * / as below:

 /* Day la chuong trinh C dau tien */ 

You cannot add a comment section inside this comment section.

Identifier in C

An identifier in C is a name used as a user-defined variable, function, and component. An identifier can start with characters A through Z, a to z and underscore (_) and 0 to 9.

C does not allow signs such as @, $, and% in identifiers. C is a language that distinguishes lowercase letters - uppercase letters . Therefore, QTM and qtm are two different identifiers in C. Here are a few valid identifiers:

 nam hoangminh abc ha_noi a_123 sinhvien _hocphi j d23b5 nhanVien 

Keywords in C

Below is a list of keywords that are reserved in the C language. Identifiers or variables, constants cannot name the same as the keywords below, otherwise the program will report an error.

White space in C

A line may contain spaces, possibly comment lines, known as white lines when the same compiler is ignored when compiling.

A space in C can be a blank paragraph, tab, newline (new line) or comment. A space divides a part of a command into parts and helps the compiler distinguish a component in a command, such as int, end the component, and start the next component as follows:

 int diemthi ; 

There must be at least one character space between int and diemthi for the compiler to understand and distinguish them. On the other hand, see the command below:

 luong = luongcoban + phucap ; // tinh tong luong 

There is no need for a space between the space and the = sign, or between = and luongcoban.

According to Tutorialspoint

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