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Assertion (software development)
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<p>In <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a>, specifically when using the <a href="/facts/Imperative_programming/6b5dUnE1">imperative programming</a> paradigm, an assertion is a <a href="/facts/Predicate_(mathematical_logic)/5WazAvKF">predicate</a> (a <a href="/facts/Boolean-valued_function/vlJBGgUl">Boolean-valued function</a> over the <a href="/facts/State_space/H1vjb3LL">state space</a>, usually expressed as a <a href="/facts/Logical_proposition/0877MFMD">logical proposition</a> using the <a href="/facts/Variable_(programming)/VoCKtwml">variables</a> of a program) connected to a point in the program, that always should evaluate to true at that point in code execution. Assertions can help a programmer read the code, help a <a href="/facts/Compiler/WNfCDFJe">compiler</a> compile it, or help the program detect its own defects. </p><p>For the latter, some programs check assertions by actually evaluating the predicate as they run. Then, if it is not in fact true – an assertion failure – the program considers itself to be broken and typically deliberately <a href="/facts/Crash_(computing)/I8yn65yt">crashes</a> or throws an assertion failure <a href="/facts/Exception_handling/VrJxgb9r">exception</a>. </p>