What is the difference between a syntax error and a runtime error?

A syntax error is a mistake in the code's structure, while a runtime error occurs during the program's execution.

A syntax error, as the name suggests, is related to the syntax or structure of the programming language. It is a type of error that occurs when the rules of the programming language are not followed correctly. For instance, missing a semicolon at the end of a statement in languages like Java or C++, or not properly closing a bracket, can lead to a syntax error. These errors are usually detected by the compiler or interpreter before the program is run, preventing it from executing until the errors are fixed. Syntax errors are often easier to fix because the compiler or interpreter typically provides information about where the error occurred and what caused it. Understanding these basic programming principles can be reinforced by exploring standard algorithms which often utilise correct syntax structures.

On the other hand, a runtime error is an error that occurs while the program is running, hence the name 'runtime'. These errors are not detected by the compiler or interpreter during the compilation or interpretation process, as they only become apparent when the program is executed. Runtime errors can be caused by a variety of issues, such as dividing by zero, attempting to access a null object, or trying to use a variable that has not been initialised. These errors can be more difficult to fix than syntax errors, as they may not always be predictable and their causes can be harder to identify. A deeper understanding of fundamental computer operations may help in predicting and mitigating potential runtime errors. Additionally, learning about identifying and correcting errors is crucial for effective debugging and ensuring software reliability.

A-Level Computer Science Tutor Summary: A syntax error happens when code doesn't follow the rules of the programming language, like missing a semicolon, and stops the program from running until it's fixed. A runtime error occurs while the program is running, caused by things like dividing by zero or using a variable that's not set up. Syntax errors are generally easier to fix than runtime errors.