Function queens_under_attack
has a Cognitive Complexity of 25 (exceeds 11 allowed). Consider refactoring. Open
function queens_under_attack($board)
{
global $attacked; // for display outside of this function
if (!is_array($board)) {
return 'ERROR';
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Method queens_under_attack
has 40 lines of code (exceeds 25 allowed). Consider refactoring. Open
function queens_under_attack($board)
{
global $attacked; // for display outside of this function
if (!is_array($board)) {
return 'ERROR';
Avoid too many return
statements within this method. Open
return 4;
Avoid too many return
statements within this method. Open
return 8;
Avoid too many return
statements within this method. Open
return 6;
Avoid too many return
statements within this method. Open
return 5;
Avoid too many return
statements within this method. Open
return 7;
The function queens_under_attack() has an NPath complexity of 204. The configured NPath complexity threshold is 200. Open
function queens_under_attack($board)
{
global $attacked; // for display outside of this function
if (!is_array($board)) {
return 'ERROR';
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NPathComplexity
Since: 0.1
The NPath complexity of a method is the number of acyclic execution paths through that method. A threshold of 200 is generally considered the point where measures should be taken to reduce complexity.
Example
class Foo {
function bar() {
// lots of complicated code
}
}
Source https://phpmd.org/rules/codesize.html#npathcomplexity
The function queens_under_attack() has a Cyclomatic Complexity of 11. The configured cyclomatic complexity threshold is 10. Open
function queens_under_attack($board)
{
global $attacked; // for display outside of this function
if (!is_array($board)) {
return 'ERROR';
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CyclomaticComplexity
Since: 0.1
Complexity is determined by the number of decision points in a method plus one for the method entry. The decision points are 'if', 'while', 'for', and 'case labels'. Generally, 1-4 is low complexity, 5-7 indicates moderate complexity, 8-10 is high complexity, and 11+ is very high complexity.
Example
// Cyclomatic Complexity = 11
class Foo {
1 public function example() {
2 if ($a == $b) {
3 if ($a1 == $b1) {
fiddle();
4 } elseif ($a2 == $b2) {
fiddle();
} else {
fiddle();
}
5 } elseif ($c == $d) {
6 while ($c == $d) {
fiddle();
}
7 } elseif ($e == $f) {
8 for ($n = 0; $n < $h; $n++) {
fiddle();
}
} else {
switch ($z) {
9 case 1:
fiddle();
break;
10 case 2:
fiddle();
break;
11 case 3:
fiddle();
break;
default:
fiddle();
break;
}
}
}
}
Source https://phpmd.org/rules/codesize.html#cyclomaticcomplexity
Reduce the number of returns of this function 9, down to the maximum allowed 3. Open
function alpha2num($alpha)
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Having too many return statements in a function increases the function's essential complexity because the flow of execution is broken each time a return statement is encountered. This makes it harder to read and understand the logic of the function.
Noncompliant Code Example
With the default threshold of 3:
function myFunction(){ // Noncompliant as there are 4 return statements if (condition1) { return true; } else { if (condition2) { return false; } else { return true; } } return false; }
Refactor this function to reduce its Cognitive Complexity from 20 to the 15 allowed. Open
function queens_under_attack($board)
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Cognitive Complexity is a measure of how hard the control flow of a function is to understand. Functions with high Cognitive Complexity will be difficult to maintain.
See
Move this "case default" clause to the end of this "switch" statement. Open
default:
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The requirement for a final case default
clause is defensive programming. The clause should either take appropriate action, or contain
a suitable comment as to why no action is taken. Even when the switch
covers all current values of an enum
, a default case
should still be used because there is no guarantee that the enum
won't be extended.
Noncompliant Code Example
switch ($param) { //missing default clause case 0: do_something(); break; case 1: do_something_else(); break; } switch ($param) { default: // default clause should be the last one error(); break; case 0: do_something(); break; case 1: do_something_else(); break; }
Compliant Solution
switch ($param) { case 0: do_something(); break; case 1: do_something_else(); break; default: error(); break; }
See
- MISRA C:2004, 15.0 - The MISRA C switch syntax shall be used.
- MISRA C:2004, 15.3 - The final clause of a switch statement shall be the default clause
- MISRA C++:2008, 6-4-3 - A switch statement shall be a well-formed switch statement.
- MISRA C++:2008, 6-4-6 - The final clause of a switch statement shall be the default-clause
- MISRA C:2012, 16.1 - All switch statements shall be well-formed
- MISRA C:2012, 16.4 - Every switch statement shall have a default label
- MISRA C:2012, 16.5 - A default label shall appear as either the first or the last switch label of a switch statement
- MITRE, CWE-478 - Missing Default Case in Switch Statement
- CERT, MSC01-C. - Strive for logical completeness
- CERT, MSC01-CPP. - Strive for logical completeness
A file should declare new symbols (classes, functions, constants, etc.) and cause no other side effects, or it should execute logic with side effects, but should not do both. The first symbol is defined on line 33 and the first side effect is on line 3. Open
<?php
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