Book 14 · Cheat sheet

Programming Languages

The languages developers write in, what each one is known for, and where you are most likely to meet it.

01Assembly Language: Assembly language is a low-level language whose instructions map almost one-to-one onto a processor's machine code, written as short mnemonics like mov and add.
Each assembly instruction usually maps to one machine instruction.
Every CPU architecture, such as x86-64, ARM64 or RISC-V, has its own assembly language.
An assembler converts assembly text into binary machine code.
02BashBourne Again Shell: Bash is a Unix shell and scripting language, the default on most Linux systems, used both to type commands interactively and to automate tasks with scripts.
Bash is a Unix shell and scripting language released in 1989.
It is the default command line on most Linux systems.
Pipes, variables, loops and functions glue programs together.
03C: C is a compiled, low-level programming language that gives direct control over memory and is used to build operating systems, drivers, and embedded software.
C compiles directly to machine code, which makes it fast and predictable.
Memory is managed manually with functions like malloc and free.
It has no classes, exceptions, or garbage collector.
04C#: C# is a statically typed, object-oriented language that runs on the .NET runtime with garbage collection and is used for web backends, desktop apps, and games.
C# is statically typed and object-oriented, with many functional features.
Code compiles to Intermediate Language (IL) that the .NET runtime turns into machine code.
Memory is managed by a garbage collector.
05C++: C++ is a compiled, statically typed language that extends C with classes and templates while keeping low-level control over memory and performance.
C++ compiles to native machine code and offers fine-grained control over performance.
It supports procedural, object-oriented, and generic programming styles.
Memory is managed through scope-based RAII and smart pointers rather than a garbage collector.
06Clojure: Clojure is a modern, dynamic dialect of Lisp that runs on the JVM, emphasizing immutable data, functional programming and interactive, REPL-driven development.
Clojure is a Lisp dialect that runs on the JVM and can use Java libraries.
Its core data structures are immutable and persistent.
Code is written as data, so macros can extend the language.
07COBOLCommon Business-Oriented Language: COBOL (Common Business-Oriented Language) is a language from 1959 for business data processing that still runs critical banking and government systems.
COBOL is a business programming language from 1959.
Its English-like syntax was meant to be readable by non-programmers.
Programs have identification, environment, data and procedure divisions.
08Dart: Dart is a statically typed, garbage-collected language from Google that compiles to native code and JavaScript, best known as the language of Flutter apps.
Dart is an object-oriented, statically typed language with sound null safety.
It compiles ahead of time to native code, and to JavaScript or WebAssembly for the web.
JIT compilation during development enables fast hot reload.
09Elixir: Elixir is a dynamic, functional language that runs on the Erlang virtual machine and is known for building fault-tolerant, highly concurrent systems.
Elixir runs on the BEAM, the Erlang virtual machine, and interoperates with Erlang code.
Lightweight processes and message passing make massive concurrency practical.
Supervisors restart failed processes, which helps systems recover automatically.
10Erlang: Erlang is a functional language created at Ericsson for telecom switches, designed for massive concurrency, fault tolerance and systems that must keep running.
Erlang was built at Ericsson for telecom systems that must run continuously.
Lightweight processes communicate by message passing and share no memory.
OTP supervisors restart failed processes, following the "let it crash" philosophy.
11F#: F# is a functional-first, statically typed language for .NET that pairs concise, type-inferred code with full access to the .NET ecosystem and C# libraries.
F# is a functional-first, statically typed language that runs on .NET.
Strong type inference means most code needs no type annotations.
Discriminated unions and pattern matching model data clearly and safely.
12FortranFormula Translation: Fortran is the first widely used high-level language, created at IBM in 1957 for science and engineering and still used in high-performance computing.
Fortran was created at IBM in 1957 for scientific computing.
It was the first widely used high-level language.
Modern standards add modules, array operations, OOP and parallelism.
13Go: Go is a compiled, statically typed language built for simplicity and fast builds, with garbage collection and built-in concurrency through goroutines.
Go compiles to a single native executable with no separate runtime to install.
It is statically typed and garbage-collected, with a deliberately small feature set.
Goroutines and channels make concurrent programs simpler to write.
14Haskell: Haskell is a purely functional, statically typed language with lazy evaluation, known for its expressive type system and mathematically precise code.
Haskell is purely functional: side effects are tracked in the type system through types like IO.
It uses lazy evaluation, computing values only when they are needed.
Its static type system infers most types and uses type classes for shared behavior.
15Java: Java is a statically typed, object-oriented programming language that compiles to bytecode for the Java Virtual Machine, so programs run on many platforms.
Java is not related to JavaScript; the similar name is a historical marketing decision.
Code compiles to bytecode that runs on the Java Virtual Machine (JVM).
It is statically typed and strongly object-oriented.
16Julia: Julia is a high-level, dynamically typed language for scientific and numerical computing, designed to be as easy to write as Python and as fast as C.
Julia is a fast, dynamic language for scientific and numerical computing.
It was announced in 2012 and reached version 1.0 in 2018.
JIT compilation through LLVM gives speed close to C.
17JVMJava Virtual Machine: The JVM runs Java bytecode, so the same compiled program works on any operating system; Kotlin, Scala and Clojure compile to that bytecode too.
The JVM runs Java bytecode, so a compiled program works on any operating system.
It manages memory with a garbage collector and speeds up hot code with a JIT compiler.
Kotlin, Scala, Clojure and Groovy also compile to JVM bytecode.
18Kotlin: Kotlin is a concise, statically typed language that runs on the JVM, works seamlessly with Java, and is widely used for Android and server-side development.
Kotlin compiles to JVM bytecode and interoperates fully with Java.
Types are non-nullable by default, which helps prevent null pointer errors.
It is statically typed with strong type inference and concise syntax.
19Lua: Lua is a small, fast scripting language designed to be embedded in other applications, making it popular for game scripting, plugins and configuration.
Lua is a tiny scripting language designed to be embedded inside other applications.
Tables are its single, flexible data structure for arrays, maps and objects.
Arrays in Lua start at index 1 by convention.
20MATLABMatrix Laboratory: MATLAB is a matrix-based language and environment from MathWorks for numerical computing, used by engineers and scientists for data analysis and simulation.
MATLAB is a language and environment for numerical, matrix-based computing.
It began in the late 1970s; MathWorks has sold it since 1984.
Toolboxes and Simulink serve engineering fields such as control and signal processing.
21Objective-C: Objective-C is an object-oriented superset of C with Smalltalk-style messaging, and it was the main language for macOS and iOS apps before Swift arrived.
Objective-C is a strict superset of C with Smalltalk-style objects and messaging.
Method calls are messages written in square brackets and dispatched at runtime.
It was the main language for macOS and iOS development before Swift.
22Perl: Perl is a mature, dynamic scripting language famous for text processing and built-in regular expressions, long used for system administration and web scripts.
Perl is a dynamic scripting language built for text processing.
Regular expressions are part of the core syntax.
Sigils like $, @ and % mark scalars, arrays and hashes.
23PHPPHP: Hypertext Preprocessor: PHP is a dynamically typed scripting language designed for web development that runs on the server to generate HTML pages and respond to browser requests.
PHP runs on the server and sends only its output, such as HTML or JSON, to the browser.
It is dynamically typed, with optional type declarations and a strict types mode.
Memory is managed automatically and released at the end of each request.
24PowerShell: PowerShell is Microsoft's command-line shell and scripting language for automating administration, passing objects rather than plain text between commands.
PowerShell is Microsoft's shell and scripting language, first released in 2006.
PowerShell 7 is open source and runs on Windows, macOS and Linux.
Cmdlets use Verb-Noun names such as Get-Process.
25Programming Language: A programming language is a formal language with exact rules for writing instructions a computer can carry out, such as Python, JavaScript, Java or C.
A programming language has exact rules (syntax) and meanings (semantics) for writing instructions.
Programs are compiled, interpreted, or compiled to bytecode for a virtual machine.
Languages range from low level, close to the hardware, to high level.
26Python: Python is a general-purpose, dynamically typed programming language known for readable syntax and wide use in data science, automation, and web backends.
Python uses indentation to define code blocks, which keeps code visually consistent.
It is dynamically but strongly typed, with optional type hints.
Memory is managed automatically through reference counting and garbage collection.
27R: R is a programming language and environment for statistics and data analysis, widely used in research for data visualization, statistical models and reports.
R is designed specifically for statistics, data analysis and graphics.
Operations are vectorized, so they apply to whole vectors without explicit loops.
Data frames are its core structure for tabular data.
28Ruby: Ruby is a dynamic, object-oriented programming language designed for developer happiness, best known for readable syntax and the Ruby on Rails web framework.
Ruby is a dynamic, object-oriented language focused on readability and developer happiness.
Everything in Ruby is an object, including numbers and nil.
Blocks and metaprogramming make concise, expressive code possible.
29Rust: Rust is a compiled, statically typed systems language that provides memory safety without a garbage collector by checking ownership rules at compile time.
Rust compiles to native machine code with performance comparable to C and C++.
Ownership and borrowing rules give memory safety without a garbage collector.
The compiler prevents data races in safe code, making concurrency safer.
30Scala: Scala is a statically typed JVM language that combines object-oriented and functional programming and is widely used for data engineering and backend systems.
Scala runs on the JVM and can use Java libraries directly.
It combines object-oriented and functional programming in one language.
Case classes, traits, pattern matching and immutable collections are central features.
31Swift: Swift is a compiled, statically typed language designed for safety and speed, used mainly to build apps for iPhone, iPad, Mac, and other Apple platforms.
Swift is the main language for building apps on Apple platforms.
It is statically typed, with optionals that make missing values explicit.
Memory is managed with Automatic Reference Counting (ARC), not a tracing garbage collector.
32Visual Basic: Visual Basic is Microsoft's family of beginner-friendly languages, including classic Visual Basic, VB.NET and VBA, which automates Office apps with macros.
Visual Basic is Microsoft's family of beginner-friendly languages.
Visual Basic 1.0 in 1991 made visual Windows app building popular.
VB.NET, from 2002, is supported but no longer gets new language features.
33Zig: Zig is a low-level systems programming language that aims to be a simpler, safer successor to C, with manual memory management and no hidden control flow.
Zig is a systems language positioned as a modern, simpler alternative to C.
Memory is managed manually through explicit allocators passed to functions.
comptime runs Zig code at compile time instead of relying on macros.