Comparison of several single-dimensional array traversal methods in PHP_PHP tutorial

Copy code The code is as follows:

//a
$arr=array('a' =>'abc','b'=>123,'c'=>true);
//b
//$arr=range('a','d');
//1
for($i=0;$iecho $arr[$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 Statement a $arr=array('a'=>'abc','b'=>123,'c'=>true); Initialize $arr to get the numeric 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 .

http://www.bkjia.com/PHPjc/324212.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/324212.htmlTechArticleCopy the code as follows: ?php //a $arr=array('a'='abc',' b'=123,'c'=true); //b //$arr=range('a','d'); //1 for($i=0;$isizeof($arr);$i++ ) echo $arr[$i].', '; echo 'br /'; //2 foreac...