php 类静态变量 和 常量消耗内存及时间对比

在对类执行100w次循环后， 常量最快，变量其次，静态变量消耗时间最高

其中：

常量消耗：101.1739毫秒

变量消耗：2039.7689毫秒

静态变量消耗：4084.8911毫秒

测试代码：

class Timer_profiler {

    public static $begin_timer;
    public static $finish_timer;
    public static $timer_html;

    /**
     * 计算时间差
     * @return type
     */
    public static function getRecordTimer() {
        return (self::getFinishTimer() - self::getBeginTimer()) * 1000;
    }

    /**
     * 生成输出HTML
     * @param type $message
     * @return type
     */
    public static function recordHtml($message = '') {
        self::setFinishTimer();
        return "<p>{$message}耗时： " . self::getRecordTimer() . " 毫秒</p>";
    }

    /**
     * 设置开始时间
     */
    public static function setBeginTimer() {
        self::$begin_timer = self::getTime();
    }

    /**
     * 设置结束时间
     */
    public static function setFinishTimer() {
        self::$finish_timer = self::getTime();
    }

    /**
     * 获取开始时间
     * @return type
     */
    public static function getBeginTimer() {
        return self::$begin_timer;
    }

    /**
     * 获取结束时间
     * @return type
     */
    public static function getFinishTimer() {
        return self::$finish_timer;
    }

    /**
     * 获取带微妙的时间戳
     * @return type
     */
    private static function getTime() {
        list($usec, $sec) = explode(" ", microtime());
        return (number_format($sec+$usec,6,'.', ''));
    }

}
function computeTime($otime,$message){
    return;
    $ntime =  xdebug_time_index();
    $str = '';
    $str .= $message . ($ntime*1000-$otime*1000);
    $str .= "<br>";
    echo $str;
}

function getMemoryUsed(){
    $str = '消耗内存<h3 style="color:red"> ';
    $str .= round(memory_get_usage()/1024/1024, 4).'MB';
    $str .= '</h3>';
    echo $str;
}

$count_i = 100*10000;
//$count_i = 100000;
Timer_profiler::setBeginTimer();
computeTime(xdebug_time_index(),'开始执行');
echo Timer_profiler::recordHtml('开始执行');
getMemoryUsed();
class TestVar {
    public $A1 = 'aaaaaaaaaaaaaaaaa';
    public $A2 = 'aaaaaaaaaaaaaaaaa';
    public $A3 = 'aaaaaaaaaaaaaaaaa';
    public $A4 = 'aaaaaaaaaaaaaaaaa';
    public $A5 = 'aaaaaaaaaaaaaaaaa';
    public $A6 = 'aaaaaaaaaaaaaaaaa';
    public $A7 = 'aaaaaaaaaaaaaaaaa';
    public $A8 = 'aaaaaaaaaaaaaaaaa';

}
$TestVar = new TestVar();
for($i=0;$i<=$count_i;$i++){
    $t = $TestVar->A1;
    $t = $TestVar->A2;
    $t = $TestVar->A3;
    $t = $TestVar->A4;
    $t = $TestVar->A5;
    $t = $TestVar->A6;
    $t = $TestVar->A7;
    $t = $TestVar->A8;
}
getMemoryUsed();
echo Timer_profiler::recordHtml('变量完成');
computeTime(xdebug_time_index(),'变量完成');

Timer_profiler::setBeginTimer();
class TestStaticVar {
    static $A1 = 'aaaaaaaaaaaaaaaaa';
    static $A2 = 'aaaaaaaaaaaaaaaaa';
    static $A3 = 'aaaaaaaaaaaaaaaaa';
    static $A4 = 'aaaaaaaaaaaaaaaaa';
    static $A5 = 'aaaaaaaaaaaaaaaaa';
    static $A6 = 'aaaaaaaaaaaaaaaaa';
    static $A7 = 'aaaaaaaaaaaaaaaaa';
    static $A8 = 'aaaaaaaaaaaaaaaaa';

}

for($i=0;$i<=$count_i;$i++){
    $t = TestStaticVar::$A1;
    $t = TestStaticVar::$A2;
    $t = TestStaticVar::$A3;
    $t = TestStaticVar::$A4;
    $t = TestStaticVar::$A5;
    $t = TestStaticVar::$A6;
    $t = TestStaticVar::$A7;
    $t = TestStaticVar::$A8;
}
getMemoryUsed();
echo Timer_profiler::recordHtml('静态变量完成');
computeTime(xdebug_time_index(),'静态变量完成');

Timer_profiler::setBeginTimer();
class TestConstVar {
    const A1 = 'aaaaaaaaaaaaaaaaa';
    const A2 = 'aaaaaaaaaaaaaaaaa';
    const A3 = 'aaaaaaaaaaaaaaaaa';
    const A4 = 'aaaaaaaaaaaaaaaaa';
    const A5 = 'aaaaaaaaaaaaaaaaa';
    const A6 = 'aaaaaaaaaaaaaaaaa';
    const A7 = 'aaaaaaaaaaaaaaaaa';
    const A8 = 'aaaaaaaaaaaaaaaaa';

}
for($i=0;$i<=$count_i;$i++){
    $t = TestConstVar::A1;
    $t = TestConstVar::A2;
    $t = TestConstVar::A3;
    $t = TestConstVar::A4;
    $t = TestConstVar::A5;
    $t = TestConstVar::A6;
    $t = TestConstVar::A7;
    $t = TestConstVar::A8;
}
getMemoryUsed();
echo Timer_profiler::recordHtml('常量完成');
computeTime(xdebug_time_index(),'常量完成');

//echo Timer_profiler::recordHtml('共执行');
computeTime(xdebug_time_index(),'共执行');
exit;