C++ Data Types

In the world of programming, data types play a crucial role. They define the type of data a variable can hold and help ensure that your code is both efficient and error-free.

In this part of our C++ course, we’ll delve into C++ data types, exploring their importance and how to use them effectively.

Data Type Characteristics

  • Bytes: Bytes represent the amount of memory a data type occupies. It’s essential to understand this because it affects how much memory your program consumes and the size of data it can handle efficiently. In the table below, we’ll provide the typical number of bytes each data type occupies.
  • Range: The range of a data type refers to the minimum and maximum values it can hold. Knowing the range is crucial for avoiding unexpected behavior in your programs. For instance, using an int to store a number that exceeds its range can lead to errors.

C++ Fundamental Data Types

Data TypeMeaningBytesRange
intInteger4 (32-bit)-2,147,483,648 to 2,147,483,647
shortShort Integer2-32,768 to 32,767
longLong Integer4 (32-bit)-2,147,483,648 to 2,147,483,647
long longLong Long Integer8 (64-bit)-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
floatSingle-Precision Floating-Point Number4Approximately ±3.4 x 10^38
doubleDouble-Precision Floating-Point Number8Approximately ±1.7 x 10^308
long doubleExtended Precision Floating-Point NumberVariesPlatform-dependent
charCharacter1-128 to 127
boolBoolean1true or false

Declaring Variables with Data Types

To declare a variable with a specific data type, use this syntax:

data_type variable_name;

For instance, to declare an integer variable named age, you’d write:

int age;

Assigning Values to Variables

After declaring a variable, assign a value using the assignment operator =

variable_name = value;


int age;
age = 25;

Alternatively, declare and initialize a variable in a single line:

data_type variable_name = value;


Data types are essential in C++, defining the kind of data variables can hold. In this segment, we explored common C++ data types, including integers, floating-point numbers, characters, and booleans. Understanding the number of bytes they occupy and their value ranges is crucial for effective programming.