0950-operators-and-expressions.md

Operators and Expressions

Operators

Operators should have one space before and after. Opening parentheses have no space after, and closing parentheses have no space before.

<?php
$a   = ($b + $c) * ($d / ($e - $f));
$foo = $bar . $baz;
$zim = $gir && $irk;

The ! operator should have a space between it and the expression it is negating.

<?php
if (! $object instanceof $class) {
    // ...
}

Increment/decrement operators should have no space separation:

<?php
$i--;
++$k;

Casts should have a space between the type and the variable.

<?php
$foo = (bool) $bar;

Expressions

Expressions for if, switch, etc. statements should fit on one line. If the expression cannot fit on one line, extract the expression into an explaining variable and use that variable as the expression. For example, the following long expression ...

<?php
if (($expression1 && $expression2 && veryLongFunctionName())
    || $expression3 || $expression4) {
    // perform some action
}

... should be rewritten as:

<?php
$set1 = $expression1 && $expression2 && veryLongFunctionName();
if ($set1 || $expression3 || $expression4) {
    // perform some action
}

If the set of expressions still cannot fit on one line, or if it would improve readability, split the expression onto several subsequent lines at the && and || operators. Operators should align with the equals sign so that the expressions themselves are also aligned.

<?php
$set1 = $expression1
     && $expression2
     && veryLongFunctionName();

$set2 = $expression3
     || $expression4;

if ($set1 || $set2) {
    // perform some action;
}