if (  cash < price )

Opposites

Notice that in the first program, the boolean expression was:

    if (  cash >= price )

because we wanted the true branch to execute when the user had enough money. In the second program, the boolean expression was:

    if (  cash < price )

because we wanted the false branch to execute when the user had enough money. Notice that the first operator includes the "equals" case, and that the second one does not.

So, in a sense ">=" and "<" are opposite of each other. Sometimes it is convenient to rearrange the contents of the true and the false branch; be sure to change the boolean expression correctly!