I have a bellow php `while` and `for` loop. 

In `while` loop it's storing `$ch_for` data in `$ch_for` array. 

Using `print_r` this array is showing these value : 

```
Array ( [ch7] => Seven [ch8] => Eight )

```

And trying to access this `array` data in `for` loop using this line :

```
echo $ch_for["ch{$x}"]; 

```

But it's showing an error message : **Illegal string offset 'ch7' in**
 ... 

**While and For Loop**

```
$ch_for     = array();
$ch_name    = array();

while ( $fetchChannel =  mysqli_fetch_array($getChannel) ) {
    $ch_id      = (int) $fetchChannel['ch_id'];
    $ch_for[$fetchChannel['ch_name']]   = htmlspecialchars($fetchChannel['ch_for']);
    $ch_name[]  = htmlspecialchars($fetchChannel['ch_name']);
}

for ($x=1; $x<=12; $x++) {
    if(  in_array('ch'.$x, $ch_name)) {
        $sel = 'checked = "checked" ';
        echo $ch_for["ch{$x}"];
    } else {
        $sel = '';
        $ch_for = '';
    }
    ?>

    <div class="checkbox form-inline">
        <label><input <?php echo $sel; ?> type="checkbox" name="ch_name[]" value="ch<?php echo $x; ?>">CH<?php echo $x; ?></label>
        <input type="text" name="ch_for[]" value="<?php echo $ch_for; ?>" placeholder="Channel details" class="form-control ch_for">
    </div>                                    
    <?php
}

```

Result of `var_dump(array_keys($ch_for));`

```
array(2) {
  [0]=>
  string(3) "ch7"
  [1]=>
  string(3) "ch8"
}

```