另一种选择是使用array_splice()。它重新排序数字键,如果你在处理足够的数据时会更快。但我更喜欢使用unset()和array_values()来提高可读性。
array_splice( $array, $index, $num_elements_to_remove);
http://php.net/manual/zh/function.array-splice.php
速度测试:
ArraySplice process used 7468 ms for its computations
ArraySplice spent 918 ms in system calls
UnsetReorder process used 9963 ms for its computations
UnsetReorder spent 31 ms in system calls
测试代码:
function rutime($ru, $rus, $index) {
return ($ru["ru_$index.tv_sec"]*1000 + intval($ru["ru_$index.tv_usec"]/1000))
- ($rus["ru_$index.tv_sec"]*1000 + intval($rus["ru_$index.tv_usec"]/1000));
}
function time_output($title, $rustart, $ru) {
echo $title . " process used " . rutime($ru, $rustart, "utime") .
" ms for its computations\n";
echo $title . " spent " . rutime($ru, $rustart, "stime") .
" ms in system calls\n";
}
$test = array();
for($i = 0; $i<100000; $i++){
$test[$i] = $i;
}
$rustart = getrusage();
for ($i = 0; $i<1000; $i++){
array_splice($test,90000,1);
}
$ru = getrusage();
time_output('ArraySplice', $rustart, $ru);
unset($test);
$test = array();
for($i = 0; $i<100000; $i++){
$test[$i] = $i;
}
$rustart = getrusage();
for ($i = 0; $i<1000; $i++){
unset($test[90000]);
$test = array_values($test);
}
$ru = getrusage();
time_output('UnsetReorder', $rustart, $ru);