Data Types I Concepts

In computer science and computer programming, a data type or simply type is an attribute of data which tells the compiler or interpreter how the programmer intends to use the data. Most programming language support common data types of real, integer and boolean. A data type constrains the values that an expression, such as a variable or a function might take. This data type defines the operations that can be done on the data, the meaning of the data, and the way values of that type can be stored. A type of value from which an expression may take its value.

Data Type Hierarchy in Python

Data types are used within type systems, which offer various ways of defining, implementing and using them. Different type systems ensure varying degrees of type safety. Almost all programming languages explicitly include the notion of data type, though different languages may use different terminology. Common data types include:

Integers
Booleans
Characters

We will be looking at the above types in detail.

Integers

An Integer is a datum of the integral data type, a data type that represents some range of mathematical integers.

These data types, usually referred to sometimes as "int" are commonly represented in a computer as a group of binary digits (bits). The size of the groupg varies, so the set of integer sizes available varies between different types of computers.

                        
                            int myInt = 4;
double myDouble = 34.1;

Above is how you can declare an Integer and a double (a floating point number) in Java. Floating point numbers can hold more bits and hence, you can declare it to be a bigger number, and also a decimal number.

Booleans

A Boolean represents two values in programming: TRUE / FALSE

In programming you may need a data type that can only have one of two values, like ON/OFF, YES/NO, TRUE,FALSE. For this, a boolean value is used in many different programming languages.

                        
                            Boolean(10 > 7);

// output true

In JavaScript, you can use a Boolean to compare variables, if 10 is greater than 7 then the output will be true, if not then it is false.

Characters

A character is any letter, number, space, punctuation mark, or symbol that can be typed on a computer. The word "computer", for example, consists of eight characters. The phrase "hi there" makes up nine characters.

Each character takes up one byte of space. The list of characters that can be typed is defined as by the ASCII and extended ASCII set.


                            char myLetter = 'p';

Above is how you declare a char data type in C++. You can also glue characters in a stream which is also known as a String.

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