howardjones/network-weathermap

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Using the same value on either side of a binary operator is almost always a mistake. In the case of logical operators, it is either a copy/paste error and therefore a bug, or it is simply wasted code, and should be simplified. In the case of bitwise operators and most binary mathematical operators, having the same value on both sides of an operator yields predictable results, and should be simplified.

This rule ignores *, +, and =.

Noncompliant Code Example

if ( $a == $a ) { // always true
  doZ();
}
if ( $a != $a ) { // always false
  doY();
}
if ( $a == $b && $a == $b ) { // if the first one is true, the second one is too
  doX();
}
if ( $a == $b || $a == $b ) { // if the first one is true, the second one is too
  doW();
}

$j = 5 / 5; //always 1
$k = 5 - 5; //always 0

Exceptions

Left-shifting 1 onto 1 is common in the construction of bit masks, and is ignored.

$i = 1 << 1; // Compliant
$j = $a << $a; // Noncompliant

See

• CERT, MSC12-C. - Detect and remove code that has no effect or is never executed
• CERT, MSC12-CPP. - Detect and remove code that has no effect
• {rule:php:S1656} - Implements a check on =.

Using the same value on either side of a binary operator is almost always a mistake. In the case of logical operators, it is either a copy/paste error and therefore a bug, or it is simply wasted code, and should be simplified. In the case of bitwise operators and most binary mathematical operators, having the same value on both sides of an operator yields predictable results, and should be simplified.

This rule ignores *, +, and =.

Noncompliant Code Example

if ( $a == $a ) { // always true
  doZ();
}
if ( $a != $a ) { // always false
  doY();
}
if ( $a == $b && $a == $b ) { // if the first one is true, the second one is too
  doX();
}
if ( $a == $b || $a == $b ) { // if the first one is true, the second one is too
  doW();
}

$j = 5 / 5; //always 1
$k = 5 - 5; //always 0

Exceptions

Left-shifting 1 onto 1 is common in the construction of bit masks, and is ignored.

$i = 1 << 1; // Compliant
$j = $a << $a; // Noncompliant

See

• CERT, MSC12-C. - Detect and remove code that has no effect or is never executed
• CERT, MSC12-CPP. - Detect and remove code that has no effect
• {rule:php:S1656} - Implements a check on =.