Exploring the Top 10 Data Types You Must Know

Updated Aug 24, 2023.
Data Types

How many data types do you know? If you think that data types are only integers, strings, and booleans, you are missing out on a lot of possibilities.

Data types are not just boring categories of data, they help programs to understand your data, store it, and process the data. Data types are vital for any programming language as they can make or break your code.

Want to know about data types? Stay with us. In this article, we will talk about different data types and see why they’re important to us. You’ll also learn how to use data types effectively in your code. Let’s get started.

What is Data Type?

Data types can be defined as:

“Categories of data that tell a computer how to store, process, and display the data.”

Think of data types as the DNA of programming. They determine what kind of values and operations are allowed for the data.

For example, the boolean data type is for logical values. You can perform logical operations on booleans but you can’t add or multiply such data. You can only apply arithmetic operations on integer data types. Understood?

So it’s not wrong to say that data types are the backbone of coding. And understanding the different data types can help you improve the readability, reliability, and efficiency of your code.

And that’s not all. Data types are also one of the main elements of a database. So they also help in gathering and utilizing all kinds of data information in various industries.

10 Common Data Types

There isn’t an exact number of data types. Because different programming languages have their specific data types depending upon the requirements of the program and the data being handled.

So which data types should you know about? The common ones.

The ones that you’ll mostly come across while coding and that are supported by almost all programming languages.

Here are the 12 most commonly used data types:

1. String

The string is a data type that represents text. It consists of a sequence of characters, such as letters, digits, symbols, and spaces, enclosed within quotation marks.

Information given in the form of data strings is easy to edit. Its storage and retrieval of data is also pretty simple.

Data information in the form of strings includes:

  • Names
  • Addresses
  • Sentences
  • Entire paragraphs

String data is widely used in various applications for handling user input and displaying messages, as well as for processing and analyzing textual data.

2. Character

Unlike string data, the character data type can store only a single character. They represent individual characters such as punctuation marks (!, ?), alphabetical letters, and symbols ($, %). So character data type can be referred to as the building block of strings.

It is one of the most basic data types in programming. Each character occupies 1 byte of storage. Characters are usually denoted by the keyword ‘char’ in most programming languages.

The character data type is used for:

  • Handling diverse languages and scripts with Unicode support.
  • Parsing, searching, and replacing specific characters or patterns within text.
  • Soring characters based on their numeric values, enabling tasks like alphabetical sorting and determining lexicographic order.

3. Boolean

The boolean is a binary data type that represents the concept of truth and false. Simply put, boolean values can only be present in two possible states; TRUE or FALSE.

Boolean values are used to control the flow of the programs based on whether the condition is correct or not.

For instance, programs use boolean variables to verify email addresses. If a user inputs the correct email, the boolean variable is set to true. If not, it is set to false.

Boolean variables can also be used to:

  • Toggle the activation or deactivation of certain features in a program
  • Validate user input by checking if it follows specific rules
  • Manage user permissions or access control in a system
  • Determine which code block or path to execute based on a given condition

Boolean values are combined with logical operators “AND”, “OR”, and “NOT” to perform complex actions.

For example, we can check if two conditions are both true using the “AND” operator, or if at least one condition is true using the “OR” operator.

With this, boolean values make our programs really powerful and help us to evaluate conditions, make decisions, and control programming loops.

4. Integer

The integer data type is used to represent whole numbers without any fractional or decimal parts. It can have either positive or negative values and it can even be zero.

The range of integer values that can be stored depends on the number of bits allocated to represent them. The allocated bits vary depending on the programming language or system, such as 8-bit, 16-bit, 32-bit, or 64-bit.

Integers are commonly used for counting, indexing, performing arithmetic operations, and representing discrete quantities.

5. Floating Point Data Type

The floating point data type is used to represent numbers with decimal points. There are two main floating point data types: Float and Double.

The float data type is a single-precision floating-point type that allows up to 7 points after a decimal. It provides a moderate level of precision, allowing for an accurate representation of decimal values within a certain range.

Floats are commonly used in applications where memory efficiency is important, but high precision is not critical.

However, it’s important to note that float values are subject to rounding errors due to the limited precision.

Single Precision vs Double Precision
Source: Javatpoint

The Double data type allows up to 15 points after a decimal. It offers a higher level of precision, allowing for a more accurate representation of decimal values over a wider range.

Although doubles provide greater precision, they consume more memory compared to floats.

Doubles are frequently used in applications that require high precision, such as scientific computations, financial calculations, and simulations.

6. Byte

A byte is a fundamental unit of storage space with digital information that consists of 8 bits. It is basically the smallest addressable unit of memory used in all sorts of computer programming, which contributes to 2.5 quintillion bytes of data generated every day.

Byte data types are commonly used to represent integer values ranging from -128 to 127. It means bytes have a limited value which makes them particularly useful for memory storage.

Data stored in bytes occupy less space as compared to larger integer types. So, it's almost like blank space byte storage.

Bytes are often used in low-level programs, such as system programming. They may also be used in embedded systems, or when working with binary data.

7. Date and Time

You can easily guess the form of data stored in this data type. Obviously, the date and time data types are used to hold information about any special dates, times specifics, or sometimes, a combination of both.

The date and time data types are used for representing temporal values like:

  • DATE
  • TIME
  • YEAR

Date and time data types allow for calculations, comparison, and formatting of date and time values thus enabling working with specific moments, durations, or intervals.

This data type is widely used in scheduling software, and apps involving time-tracking events, handling time-related calculations, etc.

8. Array and Structure Data Types

Array and structure data types are part of a bigger picture known as Composite Data Types that combine multiple data elements into a single unit.

Array data types are used to store a collection of elements of the same type. You can access the value of any element by referring to its index or position. Arrays are useful for storing and manipulating a sequence of related values.

Concept Diagram Infographic
Source: Guru99

For example, let’s say you have an array of integers representing the scores of 5 students. The array might look like this: [85, 90, 95, 80, 88].

The first element, 85, is at index 0; 90 at 1, and so on. To access a value, you have to refer to its index i.e. 0,1, or 2.

The structure data type represents a collection of data elements of different types, with each element within a structure called a member. This data type allows you to represent more complex entities by grouping together related data.

For example, let’s say you have a structure that represents a student. The structure might have fields for the student’s name (a string), age (an integer), and GPA (a floating-point number).

To access a specific value, you can simply refer to that thing like name, age, or GPA.

9. User-Defined Data Type

The user-defined data type (UDT) is a data type defined by a user, typically a programmer or developer, to represent complex data structures or objects.

User-defined data types are typically used when the built-in data types provided by the database are insufficient.

UDT allows programmers to define a custom data type that encapsulates specific characteristics, properties, and behaviors. They can easily use UDT to represent a particular entity or concept in their code.

By defining a UDT, programmers can create a data type that suits their specific needs and provides a higher level of abstraction.

UDT can easily promote code reusability, improve readability, and enhance the overall design and flexibility of a software system.

10. Null and Void

The null data type indicates the absence of a value or no value, while the void data type represents the lack of a data type and is used to indicate that a function does not return any value.

Null data type includes:

  • Null sets (code is missing)
  • Zero sets (code has no value)

The null data type is used to represent missing or undefined values in data structures.

Void data type represents:

  • Wrong code (mistake)
  • No response code (wrong function)

Void data is used by programmers for early system testing when there are no responses programmed yet for future steps.

Data Type Examples

For your ease and understanding, here's a quick way for you to know the exact difference between all these data types with examples:

Data TypeDefinitionExamples
StringSequence of characters“Hello, world!”, “Basic”, “12345”.
CharacterSingle character (alphabets, symbols)‘A', ‘b', ‘!', ‘@'.
BooleanLogical valuesTRUEFALSE
IntegerWhole numbers1, -5, 1000.
FloatDecimal point number with up to 7 digits after the decimal3.14, -2.5, 6.5464
DoubleHigh-precision decimal point number1.7976931348623157, 4.956873356373673
Byte8-bit integer‘0', ‘1', ‘2',…, ‘255'.
Date and TimeShows the date and time“2023-07-13 15:30:00”
ArrayCollection of elements of the same data type[1, 2, 3, 4, 5], [“apple”, “banana”, “orange”].
StructureCollection of elements of different typesperson {name: “John”, age: 30}, car {model: “Toyota”, year: 2021}.
User-definedCustom data type defined by the userPerson, Employee
NullNo value or absence of valuenull
VoidNo return value from a functionvoid

Importance of Data Types

You’ve learned what data types are and how they differ from each other. But why should you care? Why are data types so important for your coding success and efficiency? Here’s why:

1. Memory Efficiency

Data types allow efficient utilization of memory resources. By specifying the appropriate data type for a variable, you can ensure that only the necessary amount of memory is allocated.

This is particularly important when working with large datasets or in resource-constrained environments.

2. Data Validation

Data types enable validation and integrity checks. They help enforce constraints on the values that can be assigned to variables.

For example, using an integer data type for a variable ensures that only whole numbers can be stored, preventing accidental calculations of decimal values.

3. Computational Accuracy:

Different data types have varying levels of precision and range. Choosing the appropriate data type ensures that calculations and operations are performed accurately and efficiently.

For instance, using a double data type for financial calculations helps maintain precision in decimal values, avoiding rounding errors.

4. Data Integrity and Consistency:

By specifying data types, you can enforce consistent and meaningful data representation across different types of databases.

This promotes data integrity, reduces errors, and enhances interoperability among different components or modules.

5. Code Readability and Documentation:

Explicitly declaring data types improves code readability and documentation to a major extent. It can provide self-documentation of the expected data format.

It also allows other developers to understand the purpose and usage of variables and data structures more easily.

6. Compiler Optimization:

Compilers and interpreters can optimize code based on the declared data types. By leveraging the known characteristics of specific data types, compilers can generate more efficient machine code.

It can ultimately result in faster execution and better performance of most heavy system software.

Explore Further

Different Types of Databases
Best Database Software and Systems
What is a Data Platform?
List of Big Data Statistics

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Martin Luenendonk

Editor at FounderJar

Martin loves entrepreneurship and has helped dozens of entrepreneurs by validating the business idea, finding scalable customer acquisition channels, and building a data-driven organization. During his time working in investment banking, tech startups, and industry-leading companies he gained extensive knowledge in using different software tools to optimize business processes.

This insights and his love for researching SaaS products enables him to provide in-depth, fact-based software reviews to enable software buyers make better decisions.