Working with Array Elements

Code that stores 10 random numbers in an array

      
      $numbers = array();

      for ($i = 0; $i < 10; $i++) {

        $numbers[] = mt_rand(1, 100);
      }

Code that displays the elements of an array

      
      $numbers_string = '';

      for ($i = 0; $i < count($numbers); $i++) {

        $numbers_string .= $numbers[$i] . ' '; 

      } 

      echo($numbers_string);
      
      74 79 78 75 4 84 77 85 61 31

Code that computes the sum and average of an array of prices

      
      $prices = array(141.95, 212.95, 411, 10.95);

      $sum = 0;

      for ($i = 0; $i < count($prices); $i++) { 

        $sum += $prices[$i];

      }

      $average = $sum / count($prices);

How to skip gaps in an array

      
      $numbers = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

      unset($numbers[2], $numbers[6]);

      end($numbers);

      $last = key($numbers);

      $numbers_string = '';

      for($i = 0; $i <= $last; $i++) {

        if (isset($numbers[$i])) {

          $numbers_string .= $numbers[$i] . ' ';

        }

      }

      echo($numbers_string;) // Displays: 1 2 4 5 6 8 9 10

For loops are commonly used to process the data in arrays. In this case, the counter for the loop is used as the index for each element in the array.

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