PHP error guide

Trying to access array offset on value of type bool: meaning and fix

warning warning Affects: PHP 8.x Last verified:

Error summary

Test the producer result with === false before indexing it. Bracket access is attempted on true or false, often after a failed lookup returned false.

What it means

Test the producer result with === false before indexing it. Bracket access is attempted on true or false, often after a failed lookup returned false.

What the error means

This message means that bracket access is attempted on true or false, often after a failed lookup returned false. The exact signature distinguishes trying to access array offset on value of type bool from a generic application failure.

Why PHP produces it

The engine or service reports “Trying to access array offset on value of type bool” because its required precondition was not met. Test the producer result with === false before indexing it.

PHP version notes

The trying to access array offset on value of type bool wording here is based on PHP 8.x; punctuation and exception class names can differ on older branches or vendor builds.

Most common causes

  • The immediate input or configuration reaches the specific condition: bracket access is attempted on true or false, often after a failed lookup returned false
  • The code path assumes the prerequisite for trying to access array offset on value of type bool has already been satisfied.
  • For trying to access array offset on value of type bool, development and production differ in version, extension, permissions, paths, or service configuration.
  • An earlier operation returned an unchecked value that is consumed by the line reporting trying to access array offset on value of type bool.

Minimal examples

BAD — reproduces the problem

php 
$data = parse_ini_file("missing.ini");
echo $data["mode"];

FIXED — safer pattern

php 
$data = parse_ini_file("app.ini");
if ($data === false) { throw new RuntimeException("INI read failed"); }
echo $data["mode"];

Step-by-step diagnosis

  1. Copy the complete “Warning: Trying to access array offset on value of type bool” text and retain the first application stack frame.
  2. Reproduce trying to access array offset on value of type bool in the same SAPI and environment listed for this page.
  3. Before changing trying to access array offset on value of type bool, inspect the preceding value or directive and verify its type, path, version, and permissions.
  4. Apply the narrow correction—test the producer result with === false before indexing it—then repeat the original request once.

Fixes

Correct the failing prerequisite

Test the producer result with === false before indexing it

php 
$data = parse_ini_file("app.ini");
if ($data === false) { throw new RuntimeException("INI read failed"); }
echo $data["mode"];

Fail explicitly at the boundary

Validate the condition before the operation that emits trying to access array offset on value of type bool, and log a safe diagnostic without credentials or full production paths.

Common mistakes when fixing it

  • Suppressing trying to access array offset on value of type bool instead of correcting its upstream condition.
  • Testing trying to access array offset on value of type bool only with the CLI binary when the failing request runs under FPM or Apache.
  • Changing a global setting for trying to access array offset on value of type bool before confirming the site-specific effective configuration.

How to prevent it

  • Add a focused test that exercises the boundary responsible for trying to access array offset on value of type bool.
  • Keep runtime versions, extensions, configuration, and deploy artifacts affecting trying to access array offset on value of type bool reproducible.
  • Validate external data and service return values before they can trigger trying to access array offset on value of type bool.

Web server / environment notes

cli, fpm, linux. The failure occurs where bracket access is attempted on true or false, often after a failed lookup returned false

Tags: cli,fpm,linux

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