C language basic syntax
You have seen the basic structure of the C program in the previous lesson, so it’ll be easy to understand other basic building blocks of the C language.
Tokens in c language
A C program consists of varied tokens and a token is either a keyword, an identifier, a constant, a string literal, or a symbol. as an example, the following C statement consists of 5 tokens:
printf("Hello world"\n);the individual Tokens are:
1.printf
2. (
3. Hello World\n
4. )
5. ;
Semicolon(;)
In the C programming language, the semicolon is a statement terminator. That is, every individual statement must be ended with a semicolon. It indicates the end of one logical entity.
For example, the following are two different statements:
printf("Hello world\n); ----statement1 ended with ;
return 0; -------------------staement2 ended with ;
Comments
Comments are like helping text in your c program and they are unnoticed by the compiler. They begin with/ * and terminate with the characters */ as shown below.
/* my first program in C */
Identifiers in C programming language
A C identifier is a name used to identify a variable, function, or any other user-defined item. An identifier starts with a letter A to Z or a to z or an underscore, followed by zero or further letters, _underscores, and numerals (0 to 9). C doesn’t allow punctuation characters similar to @, $, &, # and within identifiers.
C language is a case-sensitive programming language. Therefore, Hour and hour are two different identifiers in C. Here are some examples of acceptable identifiers
Valid Identifiers :
|smooth | danny | abd | good_language | m_890 | your_name | _temp | s | hj7678 | getVar|
Keywords
Keywords are pre-defined words in the C language. Each keyword is meant to perform a specific function in a C program. Since keywords are referred names for compilers, they can’t be used as a variable name.
For example:
Here, int is a keyword that indicates a school is a variable of type int (integers).
C is a case-sensitive language, all keywords must be written in lowercase, C language has 32 keywords. here is a list of all keywords in ANSI C.
White Space in C language
A line containing only whitespace, maybe with a comment, is recognized as a blank line, and a C compiler definitely ignores it. Whitespace is the term used in C to describe blanks, tabs, newline characters, and comments.
Whitespace separates one section of a statement from every other and enables the compiler to pick out where one element in a statement, such as an int ends and the next element begins. Therefore, in the following statement:
int age;
There should be at least one whitespace character (usually a space) between int and age for the compiler to be capable to distinguish them. On the different hand, in the following statement
cars = Lamborghini + Ferrari; //get the total cars
No whitespace characters are necessary between cars and = or between = and Lamborghini, although you are free to include some if you wish for readability purposes.
