Question

关于php数组while循环问题!

<?php for($i=1;$i<=10;$i++) { $num[$i]=$i; print_r($num); echo '<br />'; } 输出结果: Array ( [1] => 1 ) Array ( [1] => 1 [2] => 2 ) Array ( [1] => 1 [2] => 2 [3] => 3 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 [7] => 7 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 [7] => 7 [8] => 8 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 [7] => 7 [8] => 8 [9] => 9 ) Array ( [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 [7] => 7 [8] => 8 [9] => 9 [10] => 10 ) 问题是: 为何在输出 第二排时，还会出现[1] => 1 呢?同理，第三排的 [3] => 3时，为何还会出现 [1] => 1 [2] => 2等等，为何不是第二排输出array([2] => 2)，第三排array([3] => 3)? 这个循环让我很头晕!极盼赐教，谢谢!

Answer 1

要不就把print_r($num);放到for循环外面，要么就在每次打印后unset($num)一下。
因为你这个$num是数组，循环一次就累加了一次，你没有清空就会一直累加。