Unlike scalar variables, which assign only a single value to a variable, an array variable can hold multiple values. Arrays are useful for holding values from database queries or web form entries, where each field (also called a “key”) holds a specific value. Let's take a look at how we define some of the arrays we use in PHP.Numbered Arrays. If the programmer does not specify a key for each value in the array, PHP automatically numbers the keys, starting from zero. This code defines an array $arrMonths[],...