PHP:访问其闭包范围之外的变量

Question

有没有办法从闭包外的闭包访问变量？例如，我想访问 $wallet关闭外:

public function generate()
{
    $this->ssh->run([
        '~/Web/gatewayd/gateway generate_wallet'
    ], function($line) use ($fn)
    {
            $wallet = data $line.PHP_EOL;
    });

    return json_decode($wallet);
}

我尝试了这个解决方案，但我觉得这既不奏效也不是一个好习惯:

public function generate()
{
    $wallet = null;
    $this->ssh->run([
        '~/Web/gatewayd/gateway generate_wallet'
    ], function($line) use ($wallet)
    {
            $wallet = $line;
    });

    return json_decode($wallet);
}

Answer 1

只需尝试:

public function generate()
{
    $wallet = null;

    $this->ssh->run([
        '~/Web/gatewayd/gateway generate_wallet'
    ], function($line) use ($fn, &$wallet)
    {
            $wallet = data $line.PHP_EOL;
    });

    return json_decode($wallet);
}