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Identifiers and keywords in C



In this section, we will learn about the keywords and reversed words in C programming that are part of the syntax. also, we will learn about the identifiers and how to name them.

Keywords

int, double, struct, switch, etc.

Identifiers

test, count, high, high-speed, etc.

now we will study identifiers and keywords in detail. we will see, how many keywords are there in C programming and all the rule for the select identifiers.

Keywords in C

Keywords are predefined, reversed words used in programming that have special meanings to the compiler. Each keyword is meant to perform a specific function in a C program. Since keywords are referred names for the compiler, they can not be used as variable names.

There are a fixed number of Keyword in the C programming language and every Keyword serve as a building block for program statements. 

There is a total of 32 keywords in C keywords written in lowercase letters.

The following table represents the keywords in C. Here is a list of some identifiers given below

 


Identifiers in C

Each program element in a C program is given a name called an identifier. Names given to identity variables, functions, and arrays are examples of identifiers. 

identifiers must be unique. they are created to give a unique name to an entity to identify it during the execution of the program.

for example

 1 int square

 2 double balance 

 3 function add()

Here, square, balance, and add() are identifiers. there is one thing that you should remember, identifier names must be different from keywords. you cannot use it as an identifier because it is a keyword.

 

The rule for an identifier

  • An identifier can only have alphanumeric characters (a-z, A-Z, 0-9) and an underscore (_).
  • The first character of an identifier can also contain the alphabet (a-z, A-Z).
  • Identifiers are also case-sensitive in C. For example, name and Name are two different identifiers in C.
  • Keywords are not allowed to be used as identifiers.
  • No special character, such as semicolons, periods, white spaces, slash, or commas are permitted to be used in or as identifiers



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