Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php |
||
| 10 | class Comparator |
||
| 11 | { |
||
| 12 | /** |
||
| 13 | * The version is equal to another. |
||
| 14 | */ |
||
| 15 | const EQUAL_TO = 0; |
||
| 16 | |||
| 17 | /** |
||
| 18 | * The version is greater than another. |
||
| 19 | */ |
||
| 20 | const GREATER_THAN = 1; |
||
| 21 | |||
| 22 | /** |
||
| 23 | * The version is less than another. |
||
| 24 | */ |
||
| 25 | const LESS_THAN = -1; |
||
| 26 | |||
| 27 | /** |
||
| 28 | * Compares one version with another. |
||
| 29 | * |
||
| 30 | * @param Version $left The left version to compare. |
||
| 31 | * @param Version $right The right version to compare. |
||
| 32 | * |
||
| 33 | * @return integer Returns Comparator::EQUAL_TO if the two versions are |
||
| 34 | * equal. If the left version is less than the right |
||
| 35 | * version, Comparator::LESS_THAN is returned. If the left |
||
| 36 | * version is greater than the right version, |
||
| 37 | * Comparator::GREATER_THAN is returned. |
||
| 38 | */ |
||
| 39 | public static function compareTo(Version $left, Version $right) |
||
| 63 | |||
| 64 | /** |
||
| 65 | * Checks if the left version is equal to the right. |
||
| 66 | * |
||
| 67 | * @param Version $left The left version to compare. |
||
| 68 | * @param Version $right The right version to compare. |
||
| 69 | * |
||
| 70 | * @return boolean TRUE if the left version is equal to the right, FALSE |
||
| 71 | * if not. |
||
| 72 | */ |
||
| 73 | public static function isEqualTo(Version $left, Version $right) |
||
| 77 | |||
| 78 | /** |
||
| 79 | * Checks if the left version is greater than the right. |
||
| 80 | * |
||
| 81 | * @param Version $left The left version to compare. |
||
| 82 | * @param Version $right The right version to compare. |
||
| 83 | * |
||
| 84 | * @return boolean TRUE if the left version is greater than the right, |
||
| 85 | * FALSE if not. |
||
| 86 | */ |
||
| 87 | public static function isGreaterThan(Version $left, Version $right) |
||
| 91 | |||
| 92 | /** |
||
| 93 | * Checks if the left version is less than the right. |
||
| 94 | * |
||
| 95 | * @param Version $left The left version to compare. |
||
| 96 | * @param Version $right The right version to compare. |
||
| 97 | * |
||
| 98 | * @return boolean TRUE if the left version is less than the right, |
||
| 99 | * FALSE if not. |
||
| 100 | */ |
||
| 101 | public static function isLessThan(Version $left, Version $right) |
||
| 105 | |||
| 106 | /** |
||
| 107 | * Compares the identifier components of the left and right versions. |
||
| 108 | * |
||
| 109 | * @param array $left The left identifiers. |
||
| 110 | * @param array $right The right identifiers. |
||
| 111 | * |
||
| 112 | * @return integer Returns Comparator::EQUAL_TO if the two identifiers are |
||
| 113 | * equal. If the left identifiers is less than the right |
||
| 114 | * identifiers, Comparator::LESS_THAN is returned. If the |
||
| 115 | * left identifiers is greater than the right identifiers, |
||
| 116 | * Comparator::GREATER_THAN is returned. |
||
| 117 | */ |
||
| 118 | public static function compareIdentifiers(array $left, array $right) |
||
| 174 | } |
||
| 175 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)or! empty(...)instead.