chapter 4: DATATYPE .....

data types are group of words used for making variables some languages are not having data types they are called typeless languages like b ,a,bcpl etc data types of foxpro character number date logical float picture memo data types in c :- char int float double short long signed unsigned WE CAN CREATE OUR OWN DATATYPES USING sruct and union DATATYPES IN VB:- byte boolean string integer float long single double date currency variant object datatypes IN C++ ,VC++ AND JAVA , the basic data types are SAME AS c , but we have object orientation with CLASS we can have object of class (object is a variable of class type datatype)

Computer uses special internal codes to keep track of different types of data it processes. This helps it to distinguish different data from one another. For example: When a programmer uses an integer in his program the computer cannot understand that it is an integer. It can also be a string. So a programmer explicitly declares his data as integer. Various data types in C programing are 1) Integer (int) 4 bytes 2) Character (char) 1byte 3) Short int (short) 2bytes 4) long int (Long) 4bytes 5) Float 4bytes Compiler on encountering a datatype in a program will allocate a fixed byte for that variable. Each type of data requires different type of memory size. If variable A is declared as int then the system would allocate 4 bytes for variable A.

it can be defined as classification of a particular type of information. It is easy for humans to distinguish between different types of data. We can usually tell at a glance whether a number is a percentage, a time, or an amount of money.Similarly, a computer uses special internal codes to keep track of the different types of data it processes.ost programming languages require the programmer to declare the data type of every data object, and most database systems require the user to specify the type of each data field. The available data types vary from one programming language to anotherbut the following usually exist in one form or another: integer : In more common parlance, whole number; a number that has no fractional part. floating-point : A number with a decimal point. For example, 3 is an integer, but 3.5 is a floating-point number. Strings:String data is non-numerical, and is used to store characters and words. All strings consist of characters enclosed within double quotation marks. The string data can include numbers and other numerical symbols but will be treated as text.

In programming, classification of a particular type of information. It is easy for humans to distinguish between different types of data. We can usually tell at a glance whether a number is a percentage, a time, or an amount of money. We do this through special symbols -- %, :, and $ -- that indicate the data's type. Similarly, a computer uses special internal codes to keep track of the different types of data it processes. Most programming languages require the programmer to declare the data type of every data object, and most database systems require the user to specify the type of each data field. The available data types vary from one programming language to another, and from one database application to another, but the following usually exist in one form or another: # integer : In more common parlance, whole number; a number that has no fractional part. # floating-point : A number with a decimal point. For example, 3 is an integer, but 3.5 is a floating-point number. # character (text ): Readable text

I don't have to define data types for PHP.

The datatype is an attribute of a variable which implicitly specifies the format and size of the variable, where the size indicates the number of bit used and the format how the bit are organized to represent the data. In C the basic datatypes are: char, 1 byte int, 2 or 4 bytes depending on the system short, 2 bytes long, 4 bytes float, 4 bytes double, 8 bytes long double, 10 bytes