PHP declare Keyword
Example
Run a function after each instruction:
<?php
$count = 0;
function example() {
global $count;
$count++;
echo "$count instructions executed<br>";
}
register_tick_function('example');
declare(ticks=1) {
$cars =
["Ford", "Volvo", "BMW"];
foreach($cars as $car) {
echo "$car <br>";
}
}
?>
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Definition and Usage
The declare keyword sets an execution directive for a block of code. If the declare
statement is not followed by a block then the directive applies to the rest of the code in the
file.
There are three directives which can be declared: ticks, encoding and
strict_types.
The ticks directive will send a tick event each time a specified number of instructions
have been executed. A tick function can be registered which will run each time a tick event
fires.
The encoding directive is used to indicate what character encoding the file is using. It
cannot be used on a block, it has to apply to the whole file.
When the strict_types directive is set, values of the wrong type passed into function
arguments with type hints will throw a fatal error instead of being cast to the correct type.
Related Pages
The enddeclare keyword.
More Examples
Example
Run a function after each instruction:
<?php
declare(strict_types=1);
function sum(int $a, int $b) {
return $a + $b;
}
// Throws a fatal error because '5' is a string instead
of a number
sum("5", 1);
?>
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❮ PHP Keywords