# apc_dec

(PECL apc >= 3.1.1)

apc_dec — Decrease a stored number

### 说明

apc_dec ( string `$key` [, int `$step` = 1 [, bool `&$success` ]] ) : int

Decreases a stored integer value.

### 参数

`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.

### 返回值

Returns the current value of `key`'s value on success, 或者在失败时返回 `FALSE`

### 范例

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)

### 参见

- apc_inc() - 递增一个储存的数字