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Learn to use hash tables

A hash table is a fundamental data structure that efficiently stores and retrieves information and is used prominently in a variety of careers, from engineers to software developers.

Learn more about what hash tables are, how to choose a learning path that works best for you, and what kinds of career options may be available to professionals with this skill set.

What is a hash table?

A hash table is a type of data structure that can help you quickly locate information. It utilizes a hash function to map specific keys to values, allowing for fast lookups and deletions of data. You can think of it like a card catalog used to find a library book by its unique identification number; the hash function allows you to quickly determine which catalog drawer contains the card for the book you are searching for.

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Choosing the right hash table program for you

Hash tables are used in a variety of jobs, such as data scientists, database administrators, and cybersecurity engineers. Online courses, certificates, and degrees are available that teach you what a hash table is and how to use it, and many can be completed within a few weeks to a few years.

Here's a closer look at some of your options for learning how to use hash tables:

Courses

You can learn about hash tables in a few weeks with online courses focusing on areas like the fundamentals of data structures and algorithms.

Certificates

Earning online professional certificates in areas like the Python programming language can provide a foundation in data structures and algorithms, including concepts that leverage hash tables.

Executive education programs

You can explore online executive education programs in subjects such as data analysis or business analytics that can teach about fast data retrieval utilizing hash tables.

Degrees

Many online degree programs in computer science are available, and they commonly include the study of hash tables as a fundamental data structure in their curriculum.

Jobs where you use hash tables

Using hash tables to accelerate data lookups is common in a number of computing jobs for various purposes, such as searching for words in a dictionary or securely storing passwords. You can apply them in fields like database administration, software development, and data science and across many industries, including technology, finance, and healthcare.

Here are a few positions that having experience with hash tables may help you qualify for, with each role's required education as well as salary data from the Bureau of Labor Statistics (BLS):

Database administrator

Database administrators often leverage hash tables to implement indexes and quickly find and retrieve data from within a database.

  • Required education: Bachelor's degree in computer science, information technology, management information systems, or a related field
  • Median annual salary (May 2023): $101,510
Software developer

Software developers use hash tables to organize and access data more efficiently and for fast lookups in various data sources such as dictionaries.

  • Required education: Bachelor's degree in software engineering, computer engineering, computer science, or a related field
  • Median annual salary (May 2023): $132,270
Data scientist

Data scientists utilize hash tables to enable faster processing and manipulation of massive amounts of information and to instantly locate specific data points.

  • Required education: Bachelor's degree in data science, computer science, mathematics, or a related field
  • Median annual salary (May 2023): $108,020

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    Frequently asked questions about hash tables

    Why should I learn hash tables?

    Hash tables are a fundamental data structure with practical applications, and learning about them can be beneficial, especially if you're an aspiring programmer. For example, you commonly use hash tables in computing to perform tasks like storing passwords or looking up words in dictionaries.

    What's the best way to learn hash tables?

    You can study hash tables through degree programs in subjects like computer science or through online courses that focus on data structures and algorithms.

    How long does it take to learn hash tables?

    You can learn about hash tables in just a few weeks by taking online courses focused on data structures and algorithms. If you're looking for a longer-term commitment, studying computer science or a related bachelor's degree usually takes about four years and covers hash tables as part of the curriculum.

    How hard is it to learn hash tables?

    Hash tables may seem intimidating in the beginning, especially if you're new to programming. But once you grasp the core concepts of what they are and how you can use them to manage data efficiently, they're relatively easy to understand.