C is a general-purpose procedural programming language that can also express low-level work such as manipulating memory directly.
Procedural means writing a program as a sequence of instructions laid out step by step, and C is the classic example. It was born at Bell Labs in the United States in the early 1970s to build UNIX, and it is still used for operating systems and embedded software today. Its source code is turned into machine code by a compiler (a program that translates the whole source in one go) before it runs, which makes it fast.
AnalogyIt is like a machine tool that lets you cut even the tiniest parts yourself: you can build almost anything, but you have to handle it with care.
How to rememberIts predecessor was called B, so the next letter of the alphabet gave it its name.
Exam points
ExamSource code written in C is translated into machine code 機械語 by a compiler コンパイラ, and what the CPU actually executes is that machine code.
Fortran is one of the very first high-level languages, designed for numerical and scientific computation.
A high-level language lets people write programs in words and formula-like notation that are easy to read, rather than in machine code. Fortran was developed at IBM in the 1950s and lets you describe calculations in a style close to mathematical formulas. It is still used today for large-scale number crunching such as weather forecasting and physics simulations.
How to rememberThe name is short for Formula Translation.
Exam points
ExamFortran is a high-level language 高水準言語 written in a formula-like style, and its programs are translated into machine code by a compiler before they run.
Java is a general-purpose object-oriented language whose programs run unchanged on any machine or OS that provides a Java Virtual Machine (JVM).
Source code
Bytecode
JVM for each OS
Run
The JVM turns the bytecode into a form that machine can run, and executes it.
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Object orientation is the idea of bundling data and the operations on it into components called objects, then building programs by combining those components. Java source code is compiled into an intermediate form called bytecode, which the JVM for each OS then executes, so the program itself does not have to be rewritten for each type of machine. A Java program downloaded from a web server and run inside the user's browser is called an applet, but applets are hardly used any more because the major browsers have dropped support for them.
AnalogyIt is like having the same standard plug adapter waiting in every country, so a single appliance works wherever you take it.
How to rememberThe name is said to come from Java, the Indonesian island famous for coffee, and its logo is a coffee cup.
Exam points
ExamBecause Java programs run on the JVM, the same program can be used without rebuilding it for each machine or OS.
ExamAn appletアプレット is a Java program sent from a web server to the user's side and executed inside the browser.
C++ is a programming language that extends C with classes and other object-oriented features.
C++ was developed in the 1980s as an extension of C, and much of C's syntax carries over unchanged. It keeps C's execution speed while making large programs easier to break into components and organize. It is used for games and for applications that demand high performance.
How to rememberIn C, ++ is the operator that adds 1 to a variable, so the name means "one step beyond C".
Exam points
Mix-upC is a procedural 手続き型 language in which you lay out steps in order, while C++ is C with object-oriented オブジェクト指向 features added on top.
Python is a general-purpose language with short, readable syntax, widely used in AI and data analysis.
Python was released in the early 1990s by Guido van Rossum of the Netherlands, and it uses indentation to mark blocks of code. It is mainly run by an interpreter (a program that interprets and executes the source one statement at a time), so you can try code as soon as you write it. It has a rich set of libraries for machine learning and data analysis, and it is also popular for teaching programming.
How to rememberThe name comes from the British comedy series Monty Python's Flying Circus, not the snake.
JavaScript is a scripting language that runs mainly in web browsers to add motion and interactivity to web pages.
A scripting language is a lightweight programming language that lets you write processing in a few short lines and run it right away. JavaScript was developed by Netscape in 1995 for its browser, and it can rewrite the content of an HTML page in response to what the user does. Besides being loaded and run by the engine built into the browser, it now also has runtime environments that run it on the server side.
AnalogyIt is like adding a pop-up mechanism to an already printed flyer, so its contents change when you open it.
Exam points
ExamRunning JavaScript code in the browser gives a web page dynamic behavior, such as a display that changes in response to what the user does.
Mix-upJava is a general-purpose language that runs on the JVM, while JavaScript is a scripting language スクリプト言語 run by engines such as those in browsers; despite the similar names, they are separate languages from different lineages.
R is a programming language built for statistical analysis and data visualization, and it is free to use as open source.
R was developed in the 1990s at the University of Auckland in New Zealand and descends from S, a language designed for statistics. Statistical functions such as averages, regression analysis and hypothesis testing come built in along with charting, and you usually run commands one at a time through an interpreter while checking the results. Add-on features for specific fields are distributed as packages.
AnalogyThink of it as a professional-grade scientific calculator dedicated to statistics and charts.
How to rememberThe name has two origins: both creators' first names start with R, and R is the letter just before S, its predecessor.
Exam points
Mix-upPython is a general-purpose language also used for the web and automation, and data analysis is just one of its uses. R is a language created specifically for statistical analysis.
Python vs. R
Aspect
Python
R
Key differenceDesigned for
General use across many fields
Statistical analysis and charting
Main users
A wide range, from web developers to data analysts
Statisticians and researchers
Key points
Source code written in C or Fortran is translated into machine code by a compiler before it runs.
Java runs on the JVM, so programs do not need to be rewritten for each machine or OS.
JavaScript runs mainly in web browsers and adds motion to web pages.
In terms of typical uses, Fortran serves scientific and engineering computation, while Python serves AI and data analysis.