Ternary operator in Ruby - Step-by-Step Execution

Concept Flow - Ternary operator

Evaluate condition

Yes↓

Return value if true

↓

End

No↓

Return value if false

↓

End

The ternary operator checks a condition and returns one value if true, another if false, all in one line.

Execution Sample

Ruby

age = 20
status = age >= 18 ? "Adult" : "Minor"
puts status

This code checks if age is 18 or more, then sets status to 'Adult' or 'Minor' accordingly, and prints it.

Execution Table

Step	Condition (age >= 18)	Result	Value assigned to status	Output
1	20 >= 18	true	"Adult"
2	N/A	N/A	N/A	Adult

💡 Condition evaluated once; since true, 'Adult' assigned and printed; execution ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2 (final)
age	undefined	20	20
status	undefined	"Adult"	"Adult"

Key Moments - 2 Insights

Why does the ternary operator use a question mark and colon?

The question mark separates the condition from the true value, and the colon separates the true value from the false value, as shown in step 1 of the execution_table.

Is the condition evaluated more than once?

No, the condition is evaluated only once at step 1, then the result decides which value is assigned.

Visual Quiz - 3 Questions

Look at the execution_table at step 1, what is the condition result?

A true

B false

C undefined

D error

💡 Hint

Check the 'Condition (age >= 18)' column at step 1 in execution_table.

At which step is the value 'Adult' assigned to status?

A Step 2

B Step 1

C Before Step 1

D Never assigned

💡 Hint

Look at the 'Value assigned to status' column in execution_table.

If age was 16, what would be the value assigned to status?

A nil

B "Adult"

C "Minor"

D error

💡 Hint

Think about the ternary operator logic shown in concept_flow and execution_table.

Concept Snapshot

Syntax: condition ? value_if_true : value_if_false
Evaluates condition once.
Returns value_if_true if condition true.
Returns value_if_false if condition false.
Used for simple if-else in one line.

Full Transcript

The ternary operator in Ruby is a short way to write an if-else statement. It first checks a condition. If the condition is true, it returns the first value after the question mark. If false, it returns the value after the colon. In the example, age is 20, which is greater or equal to 18, so the condition is true. The status variable is assigned 'Adult'. Then, the program prints 'Adult'. This operator helps write simple decisions in one line, making code shorter and easier to read.