Unit 1. Getting started (Introduction to "C") with Pavan Chavhan {Ch.2}

Hello everyone !!! Welcome back to the "technical_spc". In my last blog we discussed about the introduction of "c" language. In previous blog I had covered the :-

                               1. History of "C".

                               2. Getting started with "C".

                               3. Character set.

Lets, start the first topic of the today's blog....

Constants.

(a). Constant is a any value that cannot be changed during program execution.

(b). A constant is an entity that doesn't change whereas a variable is an entity that may change.

Variables.

(a). Variable is a data name which is used to store some data value o symbolic names for storing program.

(b). Rules for constructing variables are :

      1. First characters should be alphabet or underscore.

      2. No commas or blanks are allowed within a variable name.

      3. No special symbol other than an underscore can't be used.

Keywords.

(a). There are certain words reserved for doing specific task, these words are known as reserved word or keywords.

(b). These words are predefined and always written in lower case or small letter.

(c). Ex. :-  int, short, signed, unsigned, default, volatile, float, long, double, break, continue, typedef, static, do, for, union, return, while, do, extern, register, enum, case, goto, struct, char, auto, const, etc.

Structure of "C" program.

(a). Common line.

(b). Preprocessor directive.

(c). Global variable declaration.

(d). Main function()

        {

            Local variables;

            Statements;

            {  

              User defined function;

             }

         }

Data types.

(a). Data types refer to an extensive system used for declaring variables or functions of different types before its use.

(b). The type of a variable determines how much space it occupies in storage and how the bit pattern stored is interpreted.

(c). "C" has the following 4 types of data types :

• basic built-in data types :- int, float, double, char.
• enumeration data type :- enum.
• derived data types :- pointer, array, structure, union.
• void data types :- void.

Operators.

(a). This is a symbol use to perform some operation are variables, operands or with the constant.

(b). Some operators are :-

• Arithmetic Operator.
• Assignment Operator.
• Relational Operator.
• Increment & Decrement.
• Comma Operator.
• Logical Operator.

If you have any questions you may ask in comment below. If you are enjoyed this article, share it with your friends and colleagues!