These are the errors caused by unexpected condition encountered while executing the code that prevents the code to compile. These can be null pointer references, array out-of-bound errors,
Runtime errors happen as a user is executing your program. The code might work correctly on your machine, but on the webserver, there might be a different configuration, or it might be interacted with in a way that could cause a runtime error.
If your system took the input from a form and tried to capitalize the first letter of a name by doing something like params[:first_name].capitalize, this would break if the form was sent without a first name.
Runtime errors are particularly annoying because they directly impact your end user. A lot of these other errors will happen when you’re at your computer working on the code. These errors occur when the system is running and can stop someone from doing what they need to do.
Make sure you have good error reporting in place to capture any runtime errors and automatically open up new bugs in your ticketing system. Try and learn from each bug report so that in future you can guard against this type of error.
Making use of frameworks and community maintained code is an excellent way of minimizing these types of errors because the code is in many different projects, so it will have already encountered and fixed many issues.
Runtime errors can be particularly frustrating for developers because they can potentially affect end users directly. Unlike compile-time errors, which are caught by the compiler before the program is executed, runtime errors occur during the program’s execution and can lead to unexpected crashes, freezes, or incorrect behavior while the program is running.
Runtime errors can occur in various situations, including:
- When the program receives input that it cannot handle or violates its assumptions, for example, trying to parse a non-numeric string as an integer.
When there are problems with memory allocation, such as attempting to access memory that has not been allocated or accessing a deallocated memory location.Performing division by zero—trying to divide a number by zero results in an arithmetic exception, which halts the program's execution.
Runtime errors can be challenging to diagnose and fix, especially if they occur infrequently or under specific conditions that are difficult to replicate.
To avoid runtime errors, you can start by validating input data to ensure it meets expected criteria and does not cause unexpected behavior or errors during runtime. Perform checks for data type compatibility, range validation, and error handling for invalid input.
Adopt defensive programming techniques by implementing error-handling mechanisms, such as try-except blocks (in languages like Python) or exception-handling constructs (in languages like Java and C++).
Test the program with boundary values, extreme inputs, and edge cases to identify potential runtime errors that may occur under unusual conditions. Consider scenarios such as division by zero, out-of-bounds array access, and integer overflow.
Implement logging and monitoring mechanisms to record runtime errors, exceptions, and unexpected behavior during program execution. Analyze log files and monitoring data to diagnose runtime issues, identify root causes, and track elusive bugs.