The content of $products array is:

Element 0 is Tires
Element 1 is Oil
Element 2 is Sparc Plugs

The content of $prices array is:

Current element is Tires with value 100
Current element is Oil with value 10
Current element is Spark Plugs with value 4

The content of $products array in sorted order is:

Element 0 is Oil
Element 1 is Sparc Plugs
Element 2 is Tires

The content of $prices array sorted by key is:

Current element is Oil with value 10
Current element is Spark Plugs with value 4
Current element is Tires with value 100

The content of $prices array sorted by values is:

Current element is Spark Plugs with value 4
Current element is Oil with value 10
Current element is Tires with value 100