Php/docs/function.apcu-cas
apcu_cas
(PECL apcu >= 4.0.0)
apcu_cas — Updates an old value with a new value
说明
apcu_cas
( string $key
, int $old
, int $new
) : bool
apcu_cas() updates an already existing integer value if the
old parameter matches the currently stored value
with the value of the new parameter.
参数
key- The key of the value being updated.
old- The old value (the value currently stored).
new- The new value to update to.
返回值
成功时返回 true， 或者在失败时返回 false。
范例
Example #1 apcu_cas() example
<?phpapcu_store('foobar', 2);echo '$foobar = 2', PHP_EOL;echo '$foobar == 1 ? 2 : 1 = ', (apcu_cas('foobar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;echo '$foobar == 2 ? 1 : 2 = ', (apcu_cas('foobar', 2, 1) ? 'ok' : 'fail'), PHP_EOL;echo '$foobar = ', apcu_fetch('foobar'), PHP_EOL;echo '$f__bar == 1 ? 2 : 1 = ', (apcu_cas('f__bar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;apcu_store('perfection', 'xyz');echo '$perfection == 2 ? 1 : 2 = ', (apcu_cas('perfection', 2, 1) ? 'ok' : 'epic fail'), PHP_EOL;echo '$foobar = ', apcu_fetch('foobar'), PHP_EOL;?>
以上例程的输出类似于：
$foobar = 2 $foobar == 1 ? 2 : 1 = fail $foobar == 2 ? 1 : 2 = ok $foobar = 1 $f__bar == 1 ? 2 : 1 = fail $perfection == 2 ? 1 : 2 = epic fail $foobar = 1
