unit 3: Boolean Expressions
Boolean
True or False
if (x % 2 != 0)
x is odd
if (y != 0)
y is not zero
!=
does not equal
==
The equality operator (sometimes read: "equal equal") is used to compare two values, and returns a Boolean (true/false). Avoid confusion with the assignment operator "=",
&&
and (both)
>
greater than
>=
greater than or equal to
relational operators
have lower precedence than math && is evaluated before ||
y is a greater magnitude than x
if (Math.abs(y) > Math.abs(x))
if-then
if (condition) statement;
x is divisible by 17
if (x % 17 == 0)
x is even
if (x % 2 == 0)
x is bigger than 10 and less then 90
if (x > 10 && x < 90)
y is not a multiple (# that can be divided by another number w/o a remainder) of x
if (y % x != 0)
y is negative
if (y < 0)
y is a non-negative one-digit number
if (y >= 0 && y<=9)
short circuit && (and)
if condition is FALSE then condition is false anyways
short circuit || (or)
if conditional is TRUE then condition is true anyways
Short Circuited Operators
if the left operand is sufficient to determine the result, the right operand is not evaluated
z is less than x or z is greater than y
if(z < x || z > y)
<
less than
<=
less than or equal to
!
not (neither)
||
or (1 or the other)