Basic Data Types

• A data type specify type of the data type
• Data types are require storing different type of value for operation purpose.
• C- Language has the following basic data types.

[1] int (Integer):

• Integer data type is used to store integer value without having fractional part.
• “int” keyword is used to define integer data type variable.
• It allocated 2 byte of memory space.
• Example: 10,5, 25, 100,-50

[2] char (Character):

• Character data type is used to store character data.
• 1 byte of memory space is allocated to char data type variable.
• “char” keyword is used to declare character data type variable.
• It can store a signal character in 1 byte of memory space.
• Example: ‘a’, ‘10’, ‘hello’, ‘123’

[3] float:

• A float data type is used to store numerical value with fractional part.
• “float” keyword is use to declare float data type variable.
• 4 byte of memory space is allocated to it.
• It may store positive or negative value.
• Example:5, -0.025, 25.075

[4] double:

• Double data type is also use to store numerical value with fractional part
• Normally, float data type is use only for simple business calculations as it does not provide higher level of accuracy.
• For complex calculation such as scientific or engineering were more higher level of accuracy is require, we can use double data type.
• 8-byte of memory space is allocated to it.
• We can use “double” keyword to declare double data type variable.

[5] long:

• long data type is similar to double data type.
• It offers higher level of accuracy.
• “long”keyword is use to declare long data type variable.

Variable (Identifier)

• A variable is a named memory area that stores (holds) value.
• A variable may change its value during the program execution.
• Variable should have meaning full name.
• they are defined using data types
• They must follow the following naming convention rules:

Naming Convention Rules(Identifier rules):

• First letter must be alphabet.
• It should not be any keyword or reserved word.
• It can be up to 32 characters long.
• It should not contain any white space. We can use underscore (-) to join two words.
• Name must be meaning full.