PHP foreach loop =>

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What does “=>” mean in PHP? 6 answers

---

That is a key-value-pair enumeration. Basically, it's iterating over the collection $fields and at each iteration, it binds the variable $a to the key, and the variable $b to the value.

  foreach($fields as $a => $b)
  {
      // iterates over all key-value pairs in the collection $fields
      //   at each iteration (for each key-value pair in the collection)
      //   $a is bound to the key
      //   $b is bound to the value
  }

If you had an associative array like this:

  $collection = array(1 => 'one', 2 => 'two', 3 => 'three');

Then the following loop would print: 1: one; 2: two; 3: three; 1: one; 2: two; 3: three;

  foreach($collection as $key => $value)
  {
      echo $key.': '.$value.'; ';
  }

---

nor do I understand the use of these variables(if they are variables) in the sprint() function.

For the second part of your question, the sprintf function essentially generates a formatted string based on the format pattern, and the variables given. So:

sprintf("%20s: %sn", $b, $_REQUEST[$a]);
           ^           ^     ^
           |           |     +--- second variable parameter
           |           |                                |
           |           +---- first variable parameter   |
           |                                       |    |
           |                                       V    V
           +----------- string format            "%20s: %sn"

returns a formatted string that outputs a:

right-justified, space padded, fixed width (20 character) string representation of the first parameter (variable $b which as explained above is the value in the key-value enumeration),

followed by colon,

followed by a space, and then

followed by the string representation of the second parameter ( $_REQUEST[$a] which is a value from the $_REQUEST array, indexed by the value of the variable $a , which again, as explained above, is bound to the key in the key-value pair enumeration)

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