An if
expression is a conditional that executes a body of code only when a specified Boolean value returns true
.
Assume we had a Boolean variable called raining
:
var raining = true
We can use an if
expression to evaluate the value of raining
to determine whether or not we execute some code:
if (raining) { println("Bring an umbrella.") }
- The expression starts with the keyword,
if
. - A pair of parentheses contains a condition (
raining
) that evaluates to eithertrue
orfalse
. - Following the condition is a pair of brackets
{
and}
that holds a block of code.
The code contained within the code block of the if
expression will only execute if the condition is true
; otherwise, that code block will be ignored.
When we run the program above, we get the following output:
Bring an umbrella.
The value of raining
inside of the if
expression is true
; therefore, the instruction println("Bring an umbrella.")
gets executed.
Instructions
Your neighbor keeps forgetting what day the garbage gets picked up. You decide to create a small program to remind them when to take their garbage out.
Create an if
expression that checks if the value of isTuesday
is true
.
Inside the if
expression, create a println()
statement that outputs "Take out the trash."