Question

$a = 1;
$b = 1;
while($a <= 4) {
    $main_marks = array();

    while($b <= 4) {
        $main_marks[] = 50;
        $b++;
    }

    print_r($main_marks);
    $a++;
}

我从该代码得到的输出是：

Array (
    [0] => 50
    [1] => 50
    [2] => 50
    [3] => 50
)
Array ()
Array ()
Array ()

但我希望所有数组变量都带有值。请帮帮我。

Answer 1

在循环外创建变量。

$a = 1;
$b = 1;
$main_marks = array();
while($a <= 4) {


    while($b <= 4) {
        $main_marks[] = 50;
        $b++;
    }

    print_r($main_marks);
    $a++;
}

Answer 2

 $a=0;
 $b=0;
 while($a < 4) {
     $b = 0;
     while($b < 4) {
       $main_marks[$a][$b] = 50;
       $b++;
     }

     $a++;
 }
 print_r($main_marks);

您希望为预期输出填充多维数组。

Answer 3

<?
$main_marks = array();
for($a=0;$a<4;$a++)
{
  for($b=0;$b<4;$b++)
  {
    $main_marks[$a][$b]=50;
  }
}
print_r($main_marks);
?>

Output:
Array
([0] => Array ( [0] => 50 [1] => 50 [2] => 50 [3] => 50 )
[1] => Array ( [0] => 50 [1] => 50 [2] => 50 [3] => 50 )
[2] => Array ( [0] => 50 [1] => 50 [2] => 50 [3] => 50 )
[3] => Array ( [0] => 50 [1] => 50 [2] => 50 [3] => 50 ) )

Answer 4

将$b=1;放在外部循环中：

$a=1;
while($a <= 4) {
    $b=1;
    $main_marks = array();

    while($b <= 4) {
        $main_marks[] = 50;
        $b++;
    }

    print_r($main_marks);
    $a++;
}

现在您为每个数组重置$b计数器

如何在php中使用in循环获取数组数据

4 个答案: