What type (integer or floating point) of operator is the / in the following:

(12 + 0.0) / 7

A good answer might be:

Floating point. Adding floating point 0.0 to the integer 12 results in a floating point 12.0. Now the division is floating point because one of its operands is. This is a common programming trick.

Mixed Expression Gotcha!

Look again at the rule:

If both operands are integer, then the operation is an integer operation. If one or two operands is floating point, then the operation will be floating point.

The rule has to be applied step-by-step. Consider this expression:

( 1/2 + 3.5 ) / 2.0

What is the result? Apply the rules: innermost parentheses first, within the parentheses the highest precedence operator first:

( 1/2 + 3.5 ) / 2.0
  ---
  do first

Since both operands are integer, the operation is integer division, resulting in:

( 0 + 3.5 ) / 2.0

Now continue to evaluate the expression inside parentheses. The + operator is floating point because one of its operands is, so the parentheses evaluates to 3.5:

3.5 / 2.0

Finally do the last operation:

1.75

This is close to the result that you might have mistakenly expected if you thought both divisions were floating point. An insidious bug might be lurking in your program!

QUESTION 9:

Surely you want to try another! What is the result of evaluating this expression:

( a/b + 4) / 2

Assume that a contains 6 and b contains 12.0