Converts implicit variables into explicit ones in double-quoted strings or heredoc syntax.
The reasoning behind this rule is the following:
- When there are two valid ways of doing the same thing, using both is
confusing, there should be a coding standard to follow
- PHP manual marks "$var" syntax as implicit and "${var}" syntax as
explicit: explicit code should always be preferred
- Explicit syntax allows word concatenation inside strings, e.g.
"${var}IsAVar", implicit doesn't
- Explicit syntax is easier to detect for IDE/editors and therefore has
colors/highlight with higher contrast, which is easier to read
Backtick operator is skipped because it is harder to handle; you can use
backtick_to_shell_exec fixer to normalize backticks to strings
--- Original
+++ New
@@ -1,4 +1,4 @@
<?php
-$a = "My name is $name !";
-$b = "I live in $state->country !";
-$c = "I have $farm[0] chickens !";
+$a = "My name is ${name} !";
+$b = "I live in {$state->country} !";
+$c = "I have {$farm[0]} chickens !";The rule is part of the following rule set:
- @PhpCsFixer
- Using the @PhpCsFixer rule set will enable the
explicit_string_variablerule.