QUESTION 16:
Add parentheses to the following to show how operator precedence groups operands:
a > b && 45 <= sum || sum < a + b && d > 90
An applicant must meet two conditions:
if ( college >= 4 && ( experience >= 2 || gpa > 3.5 ) ) System.out.println("Interview applicant"); else System.out.println("Send resume to circular file.");
| Operator | precedence |
|---|---|
! | |
&& | |
|| | Low |
You have seen that when expressions mix
&& and ||
that evaluation must be
done in the correct order.
Parentheses can be used to group operands with their correct operator,
just like in arithmetic.
Also like arithmetic operators, logical operators have precedence that
determines how things are grouped in the absence of parentheses.
In an expression, the operator with the highest precedence is grouped with its operand(s) first, then the next highest operator will be grouped with its operands, and so on. If there are several logical operators of the same precedence, they will be examined left to right.
For example, say that A, B, C, and D stand for relational expressions
(things like 23 > 90).
Then,
A || B && C | means | A || (B && C) |
A && B || C && D | means | (A && B) || (C && D) |
A && B && C || D | means | ((A && B) && C) || D |
!A && B || C | means | ((!A) && B) || C |
It is common for programmers to use parentheses to group operands together rather than rely on logical operator precedence rules.
Add parentheses to the following to show how operator precedence groups operands:
a > b && 45 <= sum || sum < a + b && d > 90