How to understand the ampersand here?

<code>    /**
     * 获取各请求方法PV数
     * 
     * @param integer $interval 周期间隔
     * @param string $referenceTime 基准时间
     * @param array $domains 域名列表
     * @param array $paths 路径列表
     * @param array $methods 请求方法列表
     * @param string $pvCountOrder PV数排序 - 正序：ASC 倒序：DESC
     * @param integer $offset 结果偏移
     * @param integer $limit 结果数量
     * @param boolean &$total 结果总数
     * @return array PV数列表
     */
    public function getPvCountForMethods(
        $interval,
        $referenceTime,
        $domains = array(),
        $paths = array(),
        $methods = array(),
        $pvCountOrder = 'DESC',
        $offset = 0,
        $limit = -1,
        &$total = false    
    ) {
        // 确定请求方法PV日志表
        $logTable = $paths</code>

Help: How to understand the & symbol in the above php parameters?

Reply content:

<code>    /**
     * 获取各请求方法PV数
     * 
     * @param integer $interval 周期间隔
     * @param string $referenceTime 基准时间
     * @param array $domains 域名列表
     * @param array $paths 路径列表
     * @param array $methods 请求方法列表
     * @param string $pvCountOrder PV数排序 - 正序：ASC 倒序：DESC
     * @param integer $offset 结果偏移
     * @param integer $limit 结果数量
     * @param boolean &$total 结果总数
     * @return array PV数列表
     */
    public function getPvCountForMethods(
        $interval,
        $referenceTime,
        $domains = array(),
        $paths = array(),
        $methods = array(),
        $pvCountOrder = 'DESC',
        $offset = 0,
        $limit = -1,
        &$total = false    
    ) {
        // 确定请求方法PV日志表
        $logTable = $paths</code>

Help: How to understand the & symbol in the above php parameters?

& represents a reference to a variable in PHP.

Putting it in this code means that the pointer inside the parameter $total points to the place passed.
The PHP interpreter will not register a new variable $total in the body of this function, but directly refers to the place passed The $total variable,
If the value of $total is modified within the function body, the $total outside will also change accordingly
example:

<code><?php
$a = 1;

function foo(&$var)
{
    return $var = $var + 10;
}

echo foo($a);//11
echo $a; //11


?></code>

There are two simple types of transfer
One is value transfer
The other is reference transfer
&It is reference transfer

Should you pass by value or by reference? &$total means passing the address of $total

Look at this: This is a manual
Then, git blame filename, find the author, and beat him to death.

Supports blame killing, 9 parameters...

Reference transfer can be regarded as a pointer, pointing to the same memory address

Quote
Function:

<code>修改同一个值，因为内存地址是一样的</code>