Precedence of NOT

The NOT operator has high precedence, so it is done before arithmetic and relational operators unless you use parentheses. Examine the following:

!cost < 50 
-----  
illegal: can't use ! on an arithmetic variable

Since ! has high precedence, the above says to apply it to cost. This which won't work, because cost is an integer and NOT applies only to boolean values.

QUESTION 24:

You need new shoes. But all you can afford is a pair of shoes that costs less than fifty dollars.

Look at these fragments of code. Does each do the same thing?

if ( cost < 50  )
  System.out.println("Acceptable shoes");
else
  System.out.println("Reject these shoes");

if ( !(cost < 50)  )
  System.out.println("Reject these shoes");
else
  System.out.println("Acceptable shoes");

if (  cost >= 50 )
  System.out.println("Reject these shoes");
else
  System.out.println("Acceptable shoes");

if (  !(cost >= 50)  )
  System.out.println("Acceptable shoes");
else
  System.out.println("Reject these shoes");

Mentally try a few costs with each fragment to see if they are equivalent.

Answer:

Precedence of NOT

QUESTION 24: