Keywords and Identifiers
Let’s have a look, what is the difference between keywords and identifiers in C language:
In C, Keywords are the words that are already defined. We cannot use the keywords as a variable name. We cannot use keywords as a variable name.
The name of those words(keywords) is already known by the compiler. The keywords, sometimes, are also known as ‘Reserved Words‘.
In C, there are 32 keywords available.
In C language identifiers is the name given to variable, constant or function. There are some rules that should be kept in mind while naming the identifiers:
- An identifier can have alphanumeric characters and underscore (i.e. A-Z, a-z, 0-9, _).
- The first letter of an identifier can be an alphabet or underscore. Identifiers can’t start with numbers.
- Name of an identifier can’t be a keyword i.e. int, float, double, goto, etc.
- Identifiers are case sensitive. So, var and VAR are different.
- Identifier names cannot contain any special character.
Note: You can start the name of an identifier with _(Underscore) but for best practices, please avoid as it confuses the compiler with system-defined names.