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

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 .