php foreach速度,PHP foreach函数性能

这里有一个标准:

srand();

$asize = 1000000;

$a = array();

for ($x=1;$x<=$asize;$x++) $a[]=rand();

$i=0;

$s = microtime(true);

foreach($a as $k=>$v) {

++$a[$k];

}

$e = microtime(true);

dolog($s,$e,'FOREACH-KEY');

$i=0;

$s = microtime(true);

foreach($a as &$v) {

++$v;

}

$e = microtime(true);

dolog($s,$e, 'FOREACH-PTR');

$i=0;

$s = microtime(true);

for ($x=0;$x

++$a[$x];

}

$e = microtime(true);

dolog($s,$e,'FOR');

function awpp(&$item,$key){

++$item;

}

$s = microtime(true);

array_walk($a, 'awpp');

$e = microtime(true);

dolog($s,$e,'ARRAY_WALK');

reset($a);

$s = microtime(true);

while (list($k, $v) = each($a)) {

++$a[$k];

}

$e = microtime(true);

dolog($s,$e,'EACH');

reset($a);

$s = microtime(true);

$node = current($a);

++$node;

while($node=next($a)) {

++$node;

}

$e = microtime(true);

dolog($s,$e,'NEXT');

结果是:

FOREACH-KEY Start: 1367595478.8087210655, End: 1367595479.2945981026, DIFF: 0.4858770370

FOREACH-PTR Start: 1367595479.2946701050, End: 1367595479.4266710281, DIFF: 0.1320009232

FOR Start: 1367595479.4267220497, End: 1367595479.6769850254, DIFF: 0.2502629757

ARRAY_WALK Start: 1367595479.6770300865, End: 1367595481.1930689812, DIFF: 1.5160388947

EACH Start: 1367595481.1931140423, End: 1367595482.5088000298, DIFF: 1.3156859875

NEXT Start: 1367595482.5088429451, End: 1367595483.2801001072, DIFF: 0.7712571621

最快的

是

带指针的foreach

不带钥匙

价值。