Editing Programming language (section)

===Exception handling===
{{main|Exception handling}}
Many programming languages include exception handlers, a section of code triggered by [[runtime error]]s that can deal with them in two main ways:{{sfn|Sebesta|2012|pp=630, 634}}
*Termination: shutting down and handing over control to the [[operating system]]. This option is considered the simplest.
*Resumption: resuming the program near where the exception occurred. This can trigger a repeat of the exception, unless the exception handler is able to modify values to prevent the exception from reoccurring.
Some programming languages support dedicating a block of code to run regardless of whether an exception occurs before the code is reached; this is called finalization.{{sfn|Sebesta|2012|p=635}}

There is a tradeoff between increased ability to handle exceptions and reduced performance.{{sfn|Sebesta|2012|p=631}} For example, even though array index errors are common{{sfn|Sebesta|2012|p=261}} C does not check them for performance reasons.{{sfn|Sebesta|2012|p=631}} Although programmers can write code to catch user-defined exceptions, this can clutter a program. Standard libraries in some languages, such as C, use their return values to indicate an exception.{{sfn|Sebesta|2012|p=632}} Some languages and their compilers have the option of turning on and off error handling capability, either temporarily or permanently.{{sfn|Sebesta|2012|pp=631, 635–636}}