1.2.295. Could Use Null-Safe Object Operator¶
When the preceding function call has the potential to return null, employing the null-safe object operator can help mitigate fatal errors.
One approach is to assess the returned value prior to utilization, ensuring it is not null, and refraining from invoking methods on a null reference. Alternatively, the null-safe operator can be employed, allowing verification of the end result. If the result is null, it indicates an error.
Another approach is to use the null-safe operator when the intermediate methods returns an object or a null. When chained, the null-safe operator will prevent Fatal Error.
<?php
// direct usage, with a check on the final value
$a = foo()?->b() ?? throw new exception('something went wrong when calculating $a');
// throw as an expression is a PHP 8.0 code
// direct usage, may yield a Fatal error
foo()->b();
// indirect usage, with a check on the returned value
$a = foo();
$c = $a ? $a->b() : null;
function foo() : ?A {
return rand(0, 1) ? new A() : null;
}
class A {
function b() : string { return '';}
}
?>
See also PHP 8.0 feature focus: nullsafe methods and Nullsafe methods and properties.
1.2.295.1. Suggestions¶
Add a check on NULL before using the returned value
Update the previous method to prevent it from returning null
Use the null-safe object operator and test the result afterward
1.2.295.2. Specs¶
Short name |
Structures/CouldUseNullableOperator |
Rulesets |
|
Exakat since |
2.3.3 |
PHP Version |
With PHP 8.0 and more recent |
Severity |
Major |
Time To Fix |
Slow (1 hour) |
Precision |
Medium |
Features |
nullsafe-object-operator, nullable |
Available in |