The complexity of an expression is defined by the number of &&, || and condition ? ifTrue : ifFalse operators it contains.

A single expression's complexity should not become too high to keep the code readable.

Noncompliant Code Example

With the default threshold value of 3

if ((($condition1 && $condition2) || ($condition3 && $condition4)) && $condition5) { ... }

Compliant Solution

if ( (my_first_condition() || my_second_condition()) && my_last_condition()) { ... }