如何使用for循环PHP创建空字符串

Question

I'm trying to create for loop giving strings empty value. How I can do it?

for ($i = 1; $i <= 24; $i++) {

    $b2_ch_v = ${'b2_g_v_'.$i}['id'];
    $$b2_ch_v = '';

}

/*
result should be:
$b2_g_v_1['id'] = '';
$b2_g_v_2['id'] = '';
[...]
$b2_g_v_24['id'] = '';
*/

Answer 1

Don't use variables named like $x1, $x2, $x3. You almost always want to use arrays instead. In this case, you can use an indexed array of associative arrays. This is sometimes also called a two-dimensional array.

for ($i = 0; $i < 24; $i++) {
    $b2_ch_v[$i] = ['id' => ''];
}

Then your first element becomes:

$b2_ch_v[0]

And its named elements can be referred to via:

$b2_ch_v[0]['id']