International PHP Conference Berlin 2025

Predefined Constants

The constants below are always available as part of the PHP core.

The following constants (either the corresponding numerical value or their symbolic name) are used as a bitmask to specify which errors to report. It is possible to use bitwise operators to combine these values or mask out certain types of errors.

Tip

The name of the constants can be used within php.ini, instead of the raw numerical values to which they correspond to. However, only the |, ~, ^, !, & operators are understood within php.ini.

Warning

It is not possible to use the symbolic names outside of PHP. For example in httpd.conf the computed bitmask value must be used instead.

E_ERROR (int)
Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted. Value of the constant: 1
E_WARNING (int)
Run-time warnings (non-fatal errors). Execution of the script is not halted. Value of the constant: 2
E_PARSE (int)
Compile-time parse errors. Parse errors should only be generated by the parser. Value of the constant: 4
E_NOTICE (int)
Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script. Value of the constant: 8
E_CORE_ERROR (int)
Fatal errors that occur during PHP's initial startup. This is like an E_ERROR, except it is generated by the core of PHP. Value of the constant: 16
E_CORE_WARNING (int)
Warnings (non-fatal errors) that occur during PHP's initial startup. This is like an E_WARNING, except it is generated by the core of PHP. Value of the constant: 32
E_COMPILE_ERROR (int)
Fatal compile-time errors. This is like an E_ERROR, except it is generated by the Zend Scripting Engine. Value of the constant: 64
E_COMPILE_WARNING (int)
Compile-time warnings (non-fatal errors). This is like an E_WARNING, except it is generated by the Zend Scripting Engine. Value of the constant: 128
E_DEPRECATED (int)
Run-time deprecation notices. Enable this to receive warnings about code that will not work in future versions. Value of the constant: 8192
E_USER_ERROR (int)
User-generated error message. This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error(). Value of the constant: 256
Warning

Usage of this constant with trigger_error() is deprecated as of PHP 8.4.0. It is recommended to either throw an Exception or call exit() instead.

E_USER_WARNING (int)
User-generated warning message. This is like an E_WARNING, except it is generated in PHP code by using the PHP function trigger_error(). Value of the constant: 512
E_USER_NOTICE (int)
User-generated notice message. This is like an E_NOTICE, except it is generated in PHP code by using the PHP function trigger_error(). Value of the constant: 1024
E_USER_DEPRECATED (int)
User-generated deprecation message. This is like an E_DEPRECATED, except it is generated in PHP code by using the PHP function trigger_error(). Value of the constant: 16384
E_STRICT (int)
Run-time suggestions emitted by PHP about the executed code to ensure forward compatibility. Value of the constant: 2048
Warning

This error level is unused, and has been deprecated as of PHP 8.4.0.

E_RECOVERABLE_ERROR (int)
Legacy engine "exceptions" which correspond to catchable fatal error. Similar to Error but must be caught via a user defined error handler (see set_error_handler()). If not handled, this behaves like E_ERROR. Value of the constant: 4096

Note: This error level is effectively unused, the only case where this can happen is when interpreting an object as a bool fails. This can only happen for internal objects. The most common example, prior to PHP 8.4.0, is using a GMP instance in a conditional.

E_ALL (int)
Bit-mask that contains every single error, warning, and notice. Value of the constant: 32767
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User Contributed Notes 8 notes

up
24
Andy at Azurite (co uk)
13 years ago
-1 is also semantically meaningless as a bit field, and only works in 2s-complement numeric representations. On a 1s-complement system -1 would not set E_ERROR. On a sign-magnitude system -1 would set nothing at all! (see e.g. http://en.wikipedia.org/wiki/Ones%27_complement)

If you want to set all bits, ~0 is the correct way to do it.

But setting undefined bits could result in undefined behaviour and that means *absolutely anything* could happen :-)
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23
russthom at fivegulf dot com
12 years ago
[Editor's note: fixed E_COMPILE_* cases that incorrectly returned E_CORE_* strings. Thanks josiebgoode.]

The following code expands on Vlad's code to show all the flags that are set. if not set, a blank line shows.

<?php
$errLvl
= error_reporting();
for (
$i = 0; $i < 15; $i++ ) {
print
FriendlyErrorType($errLvl & pow(2, $i)) . "<br>\\n";
}

function
FriendlyErrorType($type)
{
switch(
$type)
{
case
E_ERROR: // 1 //
return 'E_ERROR';
case
E_WARNING: // 2 //
return 'E_WARNING';
case
E_PARSE: // 4 //
return 'E_PARSE';
case
E_NOTICE: // 8 //
return 'E_NOTICE';
case
E_CORE_ERROR: // 16 //
return 'E_CORE_ERROR';
case
E_CORE_WARNING: // 32 //
return 'E_CORE_WARNING';
case
E_COMPILE_ERROR: // 64 //
return 'E_COMPILE_ERROR';
case
E_COMPILE_WARNING: // 128 //
return 'E_COMPILE_WARNING';
case
E_USER_ERROR: // 256 //
return 'E_USER_ERROR';
case
E_USER_WARNING: // 512 //
return 'E_USER_WARNING';
case
E_USER_NOTICE: // 1024 //
return 'E_USER_NOTICE';
case
E_STRICT: // 2048 //
return 'E_STRICT';
case
E_RECOVERABLE_ERROR: // 4096 //
return 'E_RECOVERABLE_ERROR';
case
E_DEPRECATED: // 8192 //
return 'E_DEPRECATED';
case
E_USER_DEPRECATED: // 16384 //
return 'E_USER_DEPRECATED';
}
return
"";
}
?>
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15
fadhilinjagi at gmail dot com
3 years ago
A simple and neat way to get the error level from the error code. You can even customize the error level names further.

<?php
$exceptions
= [
E_ERROR => "E_ERROR",
E_WARNING => "E_WARNING",
E_PARSE => "E_PARSE",
E_NOTICE => "E_NOTICE",
E_CORE_ERROR => "E_CORE_ERROR",
E_CORE_WARNING => "E_CORE_WARNING",
E_COMPILE_ERROR => "E_COMPILE_ERROR",
E_COMPILE_WARNING => "E_COMPILE_WARNING",
E_USER_ERROR => "E_USER_ERROR",
E_USER_WARNING => "E_USER_WARNING",
E_USER_NOTICE => "E_USER_NOTICE",
E_STRICT => "E_STRICT",
E_RECOVERABLE_ERROR => "E_RECOVERABLE_ERROR",
E_DEPRECATED => "E_DEPRECATED",
E_USER_DEPRECATED => "E_USER_DEPRECATED",
E_ALL => "E_ALL"
];

echo
$exceptions["1"];
$code = 256;
echo
$exceptions[$code];
?>

Output:
E_ERROR
E_USER_ERROR

This will need updating when PHP updates the error level names. Otherwise, it works just fine.
up
15
bbrokman at gmail dot com
5 years ago
A neat way to have a place in code to control error reporting configuration :)

<?php

$errorsActive
= [
E_ERROR => FALSE,
E_WARNING => TRUE,
E_PARSE => TRUE,
E_NOTICE => TRUE,
E_CORE_ERROR => FALSE,
E_CORE_WARNING => FALSE,
E_COMPILE_ERROR => FALSE,
E_COMPILE_WARNING => FALSE,
E_USER_ERROR => TRUE,
E_USER_WARNING => TRUE,
E_USER_NOTICE => TRUE,
E_STRICT => FALSE,
E_RECOVERABLE_ERROR => TRUE,
E_DEPRECATED => FALSE,
E_USER_DEPRECATED => TRUE,
E_ALL => FALSE,
];

error_reporting(
array_sum(
array_keys($errorsActive, $search = true)
)
);

?>
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12
cl at viazenetti dot de
7 years ago
An other way to get all PHP errors that are set to be reported. This code will even work, when additional error types are added in future.

<?php
$pot
= 0;
foreach (
array_reverse(str_split(decbin(error_reporting()))) as $bit) {
if (
$bit == 1) {
echo
array_search(pow(2, $pot), get_defined_constants(true)['Core']). "<br>\n";
}
$pot++;
}
?>
up
6
kezzyhko at NOSPAM dot semysha dot ru
8 years ago
As for me, the best way to get error name by int value is that. And it's works fine for me ;)
<?php

array_flip
(array_slice(get_defined_constants(true)['Core'], 1, 15, true))[$type];

//the same in readable form
array_flip(
array_slice(
get_defined_constants(true)['Core'],
1,
15,
true
)
)[
$type]

?>
up
3
kaioker
3 years ago
super simple error code to human readable conversion:

function prettycode($code){
return $code == 0 ? "FATAL" : array_search($code, get_defined_constants(true)['Core']);
}
up
1
ErikBachmann
5 years ago
<?php
function getErrorTypeByValue($type) {
$constants = get_defined_constants(true);

foreach (
$constants['Core'] as $key => $value ) { // Each Core constant
if ( preg_match('/^E_/', $key ) ) { // Check error constants
if ( $type == $value )
return(
"$key=$value");
}
}
}
// getErrorTypeByValue()

echo "[".getErrorTypeByValue( 1 ) . "]". PHP_EOL;
echo
"[".getErrorTypeByValue( 0 ) . "]". PHP_EOL;
echo
"[".getErrorTypeByValue( 8 ) . "]". PHP_EOL;
?>

Will give
[E_ERROR=1]
[]
[E_NOTICE=8]
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