d3cfe19d7e
Co-authored-by: Marco Borgeaud <89914223+marco-antognini-sonarsource@users.noreply.github.com>
99 lines
2.7 KiB
Plaintext
99 lines
2.7 KiB
Plaintext
This rule raises an issue when a `break` or `continue` statement is used outside of a loop.
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== Why is this an issue?
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`break` and `continue` are control flow statements used inside of loops. `break` is used to break out of its innermost enclosing loop and `continue` will continue with the next iteration.
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The example below illustrates the use of `break` in a `while` loop:
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[source,python]
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----
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n = 1
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while n < 10:
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if n % 3 == 0:
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print("Found a number divisible by 3", n)
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break
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n = n + 1
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----
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This next example uses `continue` inside a `for` loop:
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[source,python]
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----
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words = ["alice", "bob", "charlie"]
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for word in words:
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if word == word[::-1]:
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print("Found a palindrome", word)
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continue
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print("This is not a palindrome", word)
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----
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Python will raise a `SyntaxError` when `break` or `continue` are used outside of `for` or `while` loops.
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If the goal is to interrupt the main program flow, `quit()`, `exit()`, ``++os._exit()++`` and `sys.exit()` are the preferred way.
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=== Code examples
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==== Noncompliant code example
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[source,python,diff-id=1,diff-type=noncompliant]
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----
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narg=len(sys.argv)
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if narg == 1:
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print('@Usage: input_filename nelements nintervals')
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break
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----
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==== Compliant solution
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[source,python,diff-id=1,diff-type=compliant]
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----
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narg=len(sys.argv)
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if narg == 1:
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print('@Usage: input_filename nelements nintervals')
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sys.exit()
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----
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== Resources
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=== Documentation
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* https://docs.python.org/3/tutorial/controlflow.html#break-and-continue-statements-and-else-clauses-on-loops[break and continue Statements]
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Remove this "xxx" statement
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'''
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== Comments And Links
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(visible only on this page)
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=== is related to: S910
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=== on 4 Nov 2014, 15:59:14 Ann Campbell wrote:
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pylint:E0103
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=== on 9 May 2016, 15:41:47 Evgeny Mandrikov wrote:
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I don't know any C/{cpp} compiler, which will allow to use "continue" outside of loop and "break" outside of switch and loop, hence not applicable.
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=== on 9 May 2016, 15:44:26 Evgeny Mandrikov wrote:
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Note that PC-Lint error codes from 1 to 199 for C and from 1001 to 1199 for {cpp} are syntax errors.
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=== on 16 May 2016, 17:06:00 Ann Campbell wrote:
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\[~evgeny.mandrikov] I guess this means that PC-Lint doesn't expect compilable code?
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=== on 16 May 2016, 17:14:19 Evgeny Mandrikov wrote:
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\[~ann.campbell.2] I suppose that it expects for proper analysis in general, but when this is not the case it generates more precise "parse error".
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=== on 16 May 2016, 17:50:32 Ann Campbell wrote:
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For the record PC-Lint rules in these ranges are Syntax errors: 1-199, 1001-1199.
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endif::env-github,rspecator-view[]
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