(PECL apc >= 3.1.1)
apc_dec — Decrease a stored number
$key
[, int $step = 1
[, bool &$success
]] )Decreases a stored integer value.
key
The key of the value being decreased.
step
The step, or value to decrease.
success
Optionally pass the success or fail boolean value to this referenced variable.
Returns the current value of key's value on success,
或者在失败时返回 FALSE
Example #1 apc_dec() example
<?php
echo "Let's do something with success", PHP_EOL;
apc_store('anumber', 42);
echo apc_fetch('anumber'), PHP_EOL;
echo apc_dec('anumber'), PHP_EOL;
echo apc_dec('anumber', 10), PHP_EOL;
echo apc_dec('anumber', 10, $success), PHP_EOL;
var_dump($success);
echo "Now, let's fail", PHP_EOL, PHP_EOL;
apc_store('astring', 'foo');
$ret = apc_dec('astring', 1, $fail);
var_dump($ret);
var_dump($fail);
?>
以上例程的输出类似于：
Let's do something with success 42 41 31 21 bool(true) Now, let's fail bool(false) bool(false)
elfi47 (2012-10-20 16:32:12)
check for errors with === FALSE or === 0
dec() will increase to 3, 2, 1, 0, -1, -2, -3....
if you check with == FALSE you will get an wrong FALSE result if the variable is on 0.