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Data Types in C++

Overview

The first thing we must understand while beginning to learn any language is the Data type in order to begin using the language's coding features. The type of data that every variable could hold is known as the data type, and examples include character, float, and integer data types. Every language has a variety of data types, thus studying each type in depth can help us use them effectively and accurately.

Scope

In this post, we will learn about the definition of data types, their various subtypes, and the syntax for using them.
Here, we would also emphasize the types of data type modifiers.

Definition of Data Types

A data type is a classification or categorization of data in computer programming based on the type of value it holds. It instructs the computer on how to read and process data. Data types are crucial concepts in programming because they control how much memory is allocated to hold data and what operations may be performed on that data.

An integer data type, for example, can only carry whole integers, whereas a floating-point data type can only handle decimal numbers. A boolean data type can only store two values: true or false, whereas a string data type can store a string of characters.

Each programming language has its own set of data types, and each data type has its own set of rules and actions available to it. Programmers can guarantee that their programs are optimized for performance and accuracy by selecting the proper data type for a certain value.

To summarise, a data type is a method of categorizing data based on its value and the activities that may be performed on it. It is a crucial notion in programming since it allows programmers to design efficient and error-free code.

Examples include:

The variable value here is of the int datatype. Depending on the compiler, the variable score can only store 2 or 4-byte integers.

In C++, data types can be broadly categorized into three main categories:-

1)Built-in data types/primitive: Data types that are built into the C++ language and supported by the compiler are referred to as built-in data types. Integer, floating-point, character, boolean, void, and pointer types are among them.

2)User-defined data types: These are data types that the programmer creates using classes and structures.

3)Derived data types: These are data types derived from built-in data types or other derived data types. They include arrays, functions, and function pointers.

• Built-in data types/primitive: Primitive data types are the fundamental data types incorporated into the C++ programming language and supported by the compiler. They are as follows:

• integer types: The keyword int can be used to represent integer data types. A single integer takes up 4 bytes and has a range of -2147483648 to 2147483647. keywords-int, short, long, and long long. As an example:
  

• Floating-point types: The keyword float is used to store floating-point numbers (decimals and exponentials). The float variable is 4 bytes in size. Keywordds-float, double, and long double.
  
  
  
• Character type: Characters are represented by the keyword char. It is 1 byte long. In C++, single quotes'' are used to enclose characters. Keyword- char.
  
  
  
• Boolean type: The boolean data type's keyword is bool. The boolean data type has two potential values: true or false. In general, Boolean values are utilized in conditional expressions and loops.
  
  
  
• Void or Valueles: A void is something that has no value. The void data type describes an entity that has no value. It is not possible to declare variables of the void type. It is solely used for functions and does not return data.

• Wide Character: The char data type is comparable to the wide-character wchar_t data type, except its size is 2 or 4 bytes rather than 1 byte. It is used to represent characters that require more memory than a single character.

Derived Data types in C++

These are data types that are descended from primitive data types or other descended data types. They include:

1) Function 

A function is a code segment or a piece of code that is defined to do a certain task. A function is frequently created to save the user from having to write the same lines of code for the same input multiple times. All of the code is integrated into a single function that may be called from anywhere. Every C++ application includes a function called main() by default. The function also includes a return type, which specifies the type of data that will be returned when the function's execution is complete. The function's return type can be any data type, including void, which indicates that there is no need to return anything once the function's execution is finished.

Here, the return type of the sum function is an integer, and the function is used to calculate the sum of 2 numbers.

2.Array

An array is a collection of elements that are retained in memory in a continuous fashion and contain the same sort of data. An array's goal is to store a large amount of data in a single variable name and sequential sequence.

Here, we have defined an integer array of size 4, which can continuously store four integer variables in memory.

3. Pointer 

Addresses are represented symbolically using pointers. Pointers hold the addresses of variables with the same datatype as the pointer. The pointer is either 4 bytes or 8 bytes in size, depending on the data type. They allow programs to generate and modify dynamic data structures, as well as emulate call-by-reference. Its generic declaration in C/C++ looks like this:

Sum holds the address of a variable of an integer datatype.

4. Reference

When we declare a variable as a reference, it becomes an alternate name for a variable that already exists. A variable can be declared as a reference by adding '&' to its declaration.

Here ref becomes the reference to integer val, and now any changes in one would be automatically reflected in the other as they both represent the same memory location.

Abstract or User-Defined Data Types in C++

The Abstract datatype, often known as the user-defined data type, is a type of data that the user defines. 

Examples of these are:

1)Class 

A Class is a component of C++ that leads to Object-Oriented programming. It is a custom data type with its own set of data members and member functions that can be accessed and utilized by creating a class instance. A class defines a data type's blueprint.

OUTPUT:-

1)Student name is: Ustola

2)Student name is: vegeta

In the above example, the student is the name of the class. We can include the data members, which are the class variables. Similarly, member functions are added to the class; for example, print(), here is the member function, and studentName is the data member. Here, st1 and st2 are the class student objects.

2)Structure

A structural datatype is a user-defined data type that mixes objects of potentially different data types into a single type.

In this case, several data types, such as an array of characters and integer data types, are joined to create a new data type based on the user's requirements.

3. Union

Union, like Structures, is used to combine several forms of data into a single user-defined data type. A union's members all have access to the same memory. In the example below, we may merge the integer and character data types into a single data type named test. In this situation, because the data sizes of the two data types, integer, and character, differ, we would utilize the larger data type as the size of the new user-defined data type test. If we modify mark, we can observe how changes in mark are reflected in var.

Here, mark and var share the same memory. Therefore, if we change any variables, the changes will automatically reflect in another variable.

4. Enumeration

An enumeration (or enum) is a data type that the user constructs in C++. It's mostly used to give integral constant names, which makes the program easier to understand and maintain. If we do not explicitly provide the integral values to the strings in enumeration, the strings will start assigning the integral values from value 0, just like in the case of 0-based indexing.

If we were given the integer value 100 to be pass and 0 as fail: if we write,

Then, the value of res would automatically be 100.

5. Typedef defined DataType

In C++, you can specify explicit new data type names using the phrase typedef. Instead of creating a new data class, typedef names an existing one. Because just the typedef declarations would need to be modified, the portability of a program might be increased by making only minor modifications. Typedef can help with self-documentation by allowing descriptive terms for standard data types.

for example:-

Now we can use longl to define the long int data type in the code.

Datatype Modifiers in C++

DataType modifiers can be used to further modify some of the core data types. There are four modifiers in C++. These modifiers can be applied to data types such as int, double, and char. They are as follows:-

1. signed

2. Unsigned

3. short

4. Long

Conclusion

Datatypes are the first thing we need to learn when learning a programming language. In this session, we learned a lot about data types, and I recommend that you practice with data types more if you want to master C++ quickly. As a result of reading the preceding article, here are some key takeaways:

1. C++ has three data types: primitive data types, abstract data types, and derived data types.

2. Primitive data types include integers, floating points, characters, Booleans, double floating points, valueless or void, and wide characters.

3. Array, function, pointer, and reference are examples of derived data types.

4. Short, long, signed, and unsigned data modifiers can be applied to data types such as int, double, char, and so on.