An exception occurs when an error or an unexpected condition arises during the execution of a program that the code cannot properly handle.
In simple terms, the program is confused and unable to continue executing.
Exceptions are typically caused by various factors, such as:
- Input Error: Invalid user input or data that doesnβt meet the expected format or requirements.
- Resource Issues: Problems accessing files, network issues, or insufficient memory.
- Logical Errors: Situations where the code encounters unexpected conditions or tries to perform an operation that isn't allowed.
When an exception occurs, it interrupts the regular execution flow of the program. If the exception is not handled properly, it can cause the program to crash or produce incorrect results. To deal with exceptions, most programming languages provide a mechanism to handle them called "exception handlers."
Exception Handling:
- Try-Catch Blocks: This is a common way to handle exceptions. Code that might throw an exception is placed within a
try
block. If an exception occurs within thetry
block, it's caught by a correspondingcatch
block where specific actions can be taken to manage the exception.
01: try {
02: // Code that might cause an exception
03: let result = 10 / 0; // This will cause a division by zero error
04: } catch (error) {
05: // Handling the exception
06: console.log("Error:", error);
07: }
- Finally Block: Some languages include a
finally
block that allows executing specific code regardless of whether an exception occurred or not. This block is typically used for cleanup operations.
01: try {
02: // Code that might cause an exception
03: let result = 10 / 0; // This will cause a division by zero error
04: } catch (error) {
05: // Handling the exception
06: console.log("Error:", error);
07: } finally {
08: // Cleanup code or actions to be performed regardless of whether an exception occurred
09: console.log("Performing cleanup");
10: }
Exception handling helps in gracefully managing errors, providing a way to recover from unexpected situations, log errors for debugging, and maintain the stability and reliability of the program.
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