What is a high-level language?

A high-level language is one written in terms close to the problem and to human language, with each statement standing for many machine operations.

State three features of a high-level language.

It uses meaningful identifiers, it provides structured constructs such as loops and selections, and it hides the registers and memory addresses of the processor.

What is meant by portability?

Portability is the ability to move a program to a different type of computer and run it there, needing at most a fresh translation rather than a rewrite.

Explain why a high-level program is more portable than a low-level one.

It is written against the rules of the language rather than the instruction set of one processor, so it only needs a translator for the new machine.

WJEC A-Level Computer Science 601-5345-3

Hardware: Architecture, Memory and Storage

Topic overview Components of a computer system and how they connect Von Neumann architecture and the CPU The fetch-execute cycle Memory and caching Parallel processing Input and output devices and their uses Secondary storage, fragmentation and defragmentation

Networks and Data Transmission

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Logic Gates and Boolean Algebra

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Data Representation and Data Types

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Database Systems

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The Operating System

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Algorithms and Programs

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Principles of Programming

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Systems Analysis

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Practical Programming

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Data Security and Integrity

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Computing, Society and the Law

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Advanced Data Structures and Logic

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Recursion, Sorting and Searching

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Programming Paradigms and Translators

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System Design and Human-Computer Interaction

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Advanced Architecture and Assembly Language

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Number Representation and Floating Point

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Databases and Distributed Systems

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Principles of Programming

High-level languages

3 things to know
AS Unit 1

Overview

Recall questions on what makes a language high-level, why translation is needed, portability and maintainability against low-level code, why one statement becomes many machine instructions, three named languages, and the drawback that comes with the productivity.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Evaluation

Name three high-level languages, and give the advantages they offer those who write and maintain a program.

Key term

Why must a program written in a high-level language be translated before it can run?

Evaluation

Give two advantages of writing in a high-level language.

Questions from this subtopic

Each one with the model answer underneath.

1
What is a high-level language?
Model answer
A high-level language is one written in terms close to the problem and to human language, with each statement standing for many machine operations.
2
State three features of a high-level language.
Model answer
It uses meaningful identifiers, it provides structured constructs such as loops and selections, and it hides the registers and memory addresses of the processor.
3
Why must a program written in a high-level language be translated before it can run?
Model answer
A processor executes only its own machine code, so the high-level statements must first be converted into that binary form by a compiler or interpreter.
4
Give two advantages of writing in a high-level language.
Model answer
A working program is produced in far less time because one statement replaces many machine instructions, and the code can be read and corrected by someone who does not know the processor.
5
What is meant by portability?
Model answer
Portability is the ability to move a program to a different type of computer and run it there, needing at most a fresh translation rather than a rewrite.
6
Explain why a high-level program is more portable than a low-level one.
Model answer
It is written against the rules of the language rather than the instruction set of one processor, so it only needs a translator for the new machine.

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