Java 3 (One week 8/25/24)

Designate a boolean variable with a value for if one is greater than two.

boolean b = 1 > 2;

Relational operators.

Operators that compare two values, resulting in a boolean value (true or false).

Relational operator for less than.

<

Relational operator for less than or equal to

<=

Relational operator for greater than.

>

Relational operator for greater than or equal to.

>=

Relational operator for equal to

==

Relational operator for not equal to.

!=

Do if statements need parentheses?

Yes

Do if statements need braces?

No

If statement syntax.

if (x > y) {

//statements

}

If-else statement syntax.

if (x > y) {

//true statements

}

else {

//false statements

}

if-else if-else syntax

In an if statement block, the “else” clause always matches with…

…the most recent “if“ clause in the block.

Nested if statement.

An if statement contained within another if statement.

Simplify:

if (even == true)

if (even)

Write a program that computes and interprets BMI.

Test cases

70kg, 2m

80kg, 2m

100kg, 2m

200kg, 2m

70kg, 2m: Underweight

80kg, 2m: Normal

100kg, 2m: Overweight

200kg, 2m: Obese

Logical operator for “not“

!

Logical operator for “and“

&&

Logical operator for inclusive “or“

||

(returns true if one or both conditions are true)

Logical operator for exclusive “or“

^

(returns true if one condition is true, but not both)

Test cases

2000:

2003:

2004:

Test cases

2000: leap year

2003: not leap year

2004: leap year

Switch statement syntax.

In a switch statement, the switch expression in parentheses must be of … data type.

char, byte, short, or int

In a switch statement, the case values must be of what data type?

The same data type as the switch expression.

The case value in a switch statement is a …1… , and therefore cannot be a …2…

1. Constant

2. Variable

What happens when a switch statement has no break statements?

All cases will be executed, starting with the case that matches the switch expression.

express using the conditional operator：

Logic errors are also called…

bugs