Comparison between LED lamps and energy-saving lamps Comparison of several single-dimensional array traversal methods in PHP

Copy codeThe code is as follows:

//a
$arr=array('a'=>'abc','b'=>123,'c'=> ;true);
//b
//$arr=range('a','d');
//1
for($i=0;$i echo $arr[$i].', ';
echo '
';
//2
foreach($arr as $key)
echo "$key, ";
echo '
';
//3
foreach($arr as $key=>$val)
echo "$key-$val, ";
echo '
';
//4
reset($arr);
while($item=each($arr)){
echo $item['key'].'-'.$item['value'].', ';
}
echo '
';
//5
reset($arr);
while(list($key,$val)=each($arr)){
echo "$key-$val, ";
}
echo '
';
?>

Use the statement a $arr=array('a'=>'abc','b'=>123,'c'=> ;true); Initialize $arr to get the numerical index array, the output is as follows:
, , ,
abc, 123, 1,
a-abc, b-123, c-1,
a-abc, b-123, c-1,
a-abc, b-123, c-1, use statement b $arr=range('a','d'); to initialize $arr to get the associative array, the output is as follows:
a, b , c, d,
a, b, c, d,
0-a, 1-b, 2-c, 3-d,
0-a, 1-b, 2-c, 3-d,
0 -a, 1-b, 2-c, 3-d, the for loop only has limited numerical indexes; for and foreach do not need to reset() the data after the traversal is completed to make it available for the next traversal, while the each method does .

The above introduces the comparison between LED lamps and energy-saving lamps and the comparison of several single-dimensional array traversal methods in PHP, including the comparison between LED lamps and energy-saving lamps. I hope it will be helpful to friends who are interested in PHP tutorials.