问题
Is there a way in PHP to select multiple array elements at once, e.g. such that in a for loop, $i = size of first set to be selected, and then subsequent increments represent selecting the next set of that size, from an array - ?
Thanks!
回答1:
I.e. instead of just looping through one array element at a time, but to loop through selected pairs instead (e.g. 3 elements, and then to do something to those 3).
there are many ways to do it.
one would be
$arr = array(1,2,3,4,5,6,7,8,9);
$new = array_chunk($arr,3);
foreach ($new as $chunk) {
print_r($chunk);// 3 elements to do something with
}
回答2:
It depends on how you want to group your elements.
$i = 4;
$source = array( 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 );
// If you want consecutive elements in the same group, i.e. the first $i elements etc
$chunks = array_chunk( $source, $i );
foreach( $chunks as $chunk )
{
// Iterate over chunk
echo '---<br />';
foreach( $chunk as $element )
{
echo $element . '<br />';
}
}
echo '---<br />';
echo '---<br />';
// Otherwise if you want consecutive elements in separate groups
$lastElement = count( $source ) - 1;
$step = ceil( count( $source) / $i );
for( $offset = 0; $offset < $step; $offset++ )
{
echo '---<br />';
for( $element = $offset; $element <= $lastElement; $element+= $step )
{
echo $source[$element] . '<br />';
}
}
echo '---<br />';
回答3:
If I understand your question right you have something like this?
$array = array( "A" => array("a","b"),
"B" => array("a","b"),
"C" => array("a","b"));
and you want to loop thought A, B, C at the same same time?
Then you can do something like this;
for($i=0;$i<=max(count($array['A']),count($array['B']),count($array['B']))){
if(count($array['A'])<=$i+1) {
echo $array['A'][$i];
}
if(count($array['B'])<=$i+1) {
echo $array['B'][$i];
}
if(count($array['B'])<=$i+1) {
echo $array['B'][$i];
}
$i++;
}
来源:https://stackoverflow.com/questions/9453040/selecting-multiple-array-elements