IGCSE Computer Science 0478 — 4.2 Programming Languages, Translators and IDEs Hangman

The 35 key terms

1source code

The instructions a programmer writes in a programming language. The CPU cannot run it until a translator turns it into machine code.

2machine code

The binary (0s and 1s) form of instructions that the CPU can run directly. Each instruction has an opcode and an operand. Programs must be translated into it to run.

3high-level language

A programming language using English-like words that is easy for people to read and write, such as Python or Java. One statement does many jobs, and it must be translated before the CPU can run it.

4low-level language

A programming language close to the CPU's instructions, such as machine code or assembly language. Each instruction is one simple CPU operation, so it is harder for people to read.

5high-level code

Code that uses familiar words, so it is easier to read and write than low-level code, which needs many detailed instructions to do the same job.

6easier to debug

Debugging is finding and fixing errors. It is easier in short, readable high-level code than in long, hard-to-read low-level code, and translators give clearer error messages for it.

7machine independent

A language whose code can run on different types of computer. High-level languages are machine independent (portable); low-level languages are machine dependent.

8direct hardware control

Low-level code can work directly with hardware, such as registers and memory locations, which high-level languages usually hide from the programmer.

9high-level vs low-level

High-level is easy to read, debug and portable but gives less hardware control; low-level is hard to read and machine dependent but gives direct hardware control.

10choose language level

Pick high-level for portable programs on many machines; pick low-level for direct hardware control, like drivers. Then justify the choice by linking it to the task's needs.

11mnemonic

A short, memorable code in assembly language, such as LDA, ADD or STO, that stands for one machine code instruction and is easier to remember than binary.

12assembler

A translator that converts an assembly language program into machine code, so the CPU can run it. Each mnemonic becomes one machine code instruction.

13translator

Software that converts high-level or assembly code into machine code, because the CPU can only run machine code. Types: assembler, compiler, interpreter.

14syntax error

Code that breaks the rules of the language, like a missing bracket. The translator reports it and its line. A run-time error only occurs when the program runs.

15compiler

A translator that converts a whole high-level language program into machine code in one go, before the program is run. The machine code can then run without the source code.

16executable file

The machine code program a compiler produces. It runs without the compiler or source code, needs no re-translation, and works only on the type of machine it was made for.

17compiler error report

A list of every error found after the compiler checks the whole program, with line numbers and error types. No executable is made and nothing runs until all are fixed.

18interpreter

A translator that translates a high-level program one line at a time and runs each line straight away. It makes no executable file, so the source code and interpreter are needed on every run.

19stops at first error

An interpreter runs code line by line and halts at the first error it finds, reporting only that one. Earlier lines have already run. Later errors stay hidden until you fix it and run again.

20compiled program

A program translated all at once into an executable. It runs faster, needs no compiler to run, keeps the source code private, and gives a whole-program error report.

21compiler disadvantages

A compiler must translate the whole program without errors before any of it runs, and its executable only works on one machine type, so testing small changes is slow.

23line by line every run

An interpreter translates the source code again on every run, so programs run slower and need the interpreter and source code each time. Only one error is shown at a time.

24compiler vs interpreter

A compiler translates the whole program into an executable before it runs; an interpreter translates and runs line by line, stopping at the first error, with no executable.

25interpreter for development, compiler for release

Use an interpreter while developing to test and fix code quickly, then compile the final program once into a fast executable to give users without the source code.

26choose a translator

Pick an assembler for assembly code, an interpreter while testing a program, or a compiler for release to customers, then justify your choice using 'because'.

27IDE

Integrated development environment: one program, such as IDLE, Thonny or Visual Studio, with the tools to write, run and test code. It is not a language or a translator.

28code editor

The part of an IDE where you type and edit source code. It shows line numbers and syntax highlighting (colour-coded keywords), which a plain text editor does not.

29run-time environment

An IDE feature that lets you run your program and see it work, including its input and output, without leaving the IDE. It has a run button, a console and can step through code.

30built-in translator

A compiler or interpreter built into an IDE, so the programmer can translate and run code from one button without needing separate translator software.

31error diagnostics

An IDE tool that finds errors in code and tells the programmer where they are and what kind they are, using line numbers, error messages, highlighting and debugging tools.

32auto-completion

An IDE feature that suggests or finishes a keyword, function or variable name as you start typing it. It saves time and cuts spelling mistakes in names.

33auto-correction

An IDE feature that fixes, or suggests fixes for, simple mistakes like a misspelt keyword or a missing bracket. The programmer can accept the fix, so fewer syntax errors occur.

34prettyprint

An IDE feature that shows code in a clear layout, using colours for keywords and indentation for blocks, so it is easy to read. It changes only the display, not the code.

35IDE function

A built-in IDE tool that solves one programmer problem, so you match a need (typing, running, finding errors, saving typing, fixing, tidying) to the right function.

36point because reason

A full-mark answer states a point with the correct term, then links it to a reason, e.g. a compiler runs faster because the whole program is already translated.