Programming, Data Structures & Algorithms

DATA TYPES : C supports several different types of data, each of which may be represented differently within the computer’s memory. There are Tow Data  type in C programming Language. They are: Primary Data type  and secondary Data type   Primary Data type :  Primary data types consist following data types: Integer types Floating Point Types  Character Types  Double 2.Secondary data types:  Array Pointer Union Enum etc

IDENTIFIER : ldentzfiers are names that are given to various program elements, such as variables, functions and arrays. Identifiers consist of letters and digits, in any order, except that the first character must be a letter. Both  upper- and lowercase letters are permitted, though common usage favors the use of lowercase letters for most  types of identifiers. Upper- and lowercase letters are not interchangeable .  The underscore character ( - ) can also be included, and is  considered to be a letter. An underscore is often used in the middle of an identifier. An identifier may also  begin with an underscore, though this is rarely done in practice. An identifier can be arbitrarily long. Some implementations of C recognize only the first eight characters,  though most implementations recognize more (typically, 3 1 characters). Additional characters are carried  along for the programmer's convenience.  

Function is much important when we have to do a long project. Let we have a math function (sum, sub,mul etc.) in our project we need the same calculation several times. if we have a function. We can do it by a single line (by calling the function). Otherwise we will have to rewrite the same code of calculation again. And function got arbitrarily long.