Julia Ternary Operators
A ternary operator picks one of two values based on a condition. It writes a short choice in a single expression.
A ternary pick can be stored in a variable
The age check is true, so the first value is stored. Printing the variable shows the pick.
age = 20
label = age >= 18 ? "Adult" : "Child"
println(label)A ternary pick works inside println
The score check is false, so println receives the second value. Only that word prints.
score = 47
println(score >= 50 ? "Pass" : "Fail")A ternary pick can test a remainder
Seven has a remainder of 1 when divided by 2. The pick is therefore the second word.
n = 7
kind = n % 2 == 0 ? "even" : "odd"
println("7 is $kind")Example
temperature = 31
feeling = temperature >= 30 ? "hot" : "mild"
println(feeling)
println(temperature >= 30 ? "Drink water" : "Enjoy")Key points
- Ternary operator: a short expression written as condition ? first value : second value.
- Condition: the part before the question mark gives true or false.
- True branch: the value after the question mark is picked when the condition is true.
- False branch: the value after the colon is picked when the condition is false.
- Result: the whole expression gives one value, so it can be stored in a variable.
- Use it for short picks between two values.
In this example, temperature is 31, so the check temperature >= 30 is true. The first ternary stores the word hot in feeling and the program prints it. The second ternary sits inside println and picks the first message.
Note
A ternary choice is an expression, while an if statement is a block that runs code.
Try it Yourself
Edit the code, then press Run.
Running is simulated · JuliaHub
Exercise
What is the value of x after this code runs? x = 3 > 2 ? 10 : 20