PHP坚持循环练习

Question

I am stuck with this php loop. Then n = 3, k = 5, s = 21. Can anyone help me please ?

Rows 3. In the first row 5 chairs:
1 row: ⑁⑁⑁⑁⑁ (5 chairs)
2 row: ⑁⑁⑁⑁⑁⑁⑁ (7 chairs)
3 row: ⑁⑁⑁⑁⑁⑁⑁⑁⑁ (9 chairs)
Chairs in total: 21

<?php
 for ($i=0; $i<=6; $i++) {
      for ($j=0; $j<$i; $j++) {
         if($i == 1) {
             echo ''; 
         }else{
               echo '&#9281'; 
             } 
        } echo ' '; 
      }
 ?> 

Answer 1

I think you want to use 'if' syntax. Is it right? If it's not correct, You should describe your work more detail

<?php
// ...

for($i = 0; $i< sizeof($rows); $i++ ){
  if ($i % 2 == 0) {
    print "It's even";
  }
}

// ... If a row is an Array, use this one.

for($i = 0; $i< sizeof($rows); $i++ ){
  for($j = 0; $j< sizeof($rows[$i]); $j++ ){
    if ($j % 2 == 0) {
      print "It's even index of a row";
      //do Something.
    }
  }
}
?>

Answer 2

Example: When n = 3 and k = 8, it must be obtained that order s = 30 chairs.

Create a PHP solution that specifies the N-row queue in the variables, K-how many chairs should be in the first row.

For example: N = 3; K = 5;

After loading the page (after performing the program actions with the variables available) the following should be displayed:

Rows 3. First row 5 chairs: Queue 1: ⑁⑁⑁⑁⑁ (5 chairs) Queue 2: ⑁⑁⑁⑁⑁⑁⑁ (7 chairs) Queue 3: ⑁⑁⑁⑁⑁⑁⑁⑁⑁ (9 chairs) Total required chairs: 21

Answer 3

If I understand correctly what you want, $n is number of row you needed, $k number of chair at row 1.

Each row chair is added by two.

<?php
$n = 3;
$k = 5;
for($i = 0; $i < $n; $i++) {
    if($i >= 1) {
        echo PHP_EOL;
    }
    echo str_repeat('-', $k + ($i * 2));
}