Why is this an issue?

Duplicated string literals make the process of refactoring complex and error-prone, as any change would need to be propagated on all occurrences.

Exceptions

No issue will be raised on:

• strings with less than 5 characters
• strings with only letters, numbers, underscores, hyphens and periods

How to fix it

Use constants to replace the duplicated string literals. Constants can be referenced from many places, but only need to be updated in a single place.

Code examples

Noncompliant code example

With the default threshold of 3:

function run() {
  prepare('this is a duplicate'); // Noncompliant - 'this is a duplicate' is duplicated 3 times
  execute('this is a duplicate');
  release('this is a duplicate');
}

Compliant solution

MESSAGE = 'this is a duplicate';

function run() {
  prepare(MESSAGE); // Compliant - the duplicated string literal is replaced by a constant and can be safely re-used
  execute(MESSAGE);
  release(MESSAGE);
}

$severity = $request->getParam('severity-score');