fruits.php

$fruits = array('banana', 'melon', 'orange');

function joinFruits($fruits) {
  $result = '';
  foreach ($fruits as $fruit) {
    $result .= $fruit;
  }
  return $result;
}

$fruits_str = joinFruits($fruits);

var_dump($fruit); // => undefined variable error
var_dump($fruits_str); // => bananamelonorange