我也不懂。。求教

<?php?

echo $m1 = memory_get_usage();?

echo "<br />";

?

echo $m2 = memory_get_usage()-$m1;?

echo "<br />";

?

echo $m3 = memory_get_usage()-$m1-$m2;?

echo "<br />";

?

echo $m4 = memory_get_usage()-$m1-$m2-$m3;?

echo "<br />";

?

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;?

?>

大神請(qǐng)問(wèn)一下

echo $m2 = memory_get_usage()-$m1;?

echo "<br />";

這個(gè)是什么意思右邊為什么顯示144呢

怎么看不明白，能說(shuō)詳細(xì)點(diǎn)嗎