Spaceship operator (<=>) in Ruby - Step-by-Step Execution

Concept Flow - Spaceship operator (<=>)

Compare a and b

↓

Is a < b?

Yes→Return -1

No↓

Is a == b?

Yes→Return 0

No↓

Return 1 (a > b)

The spaceship operator compares two values and returns -1, 0, or 1 depending on whether the first is less than, equal to, or greater than the second.

Execution Sample

Ruby

result = 5 <=> 10
puts result

Compares 5 and 10, then prints the comparison result.

Execution Table

Step	Expression	Comparison	Result
1	5 <=> 10	5 < 10	-1
2	puts result	Prints result	-1

💡 Comparison done, result printed, program ends.

Variable Tracker

Variable	Start	After Comparison	Final
result	nil	-1	-1

Key Moments - 3 Insights

Why does 5 <=> 10 return -1 instead of true or false?

The spaceship operator returns -1, 0, or 1 to show order, not a boolean. See execution_table step 1 where 5 < 10 returns -1.

What happens if both values are equal?

If values are equal, the operator returns 0. This is shown in the flow where equality leads to 0.

Why is the result stored in a variable before printing?

Storing allows reuse or further checks. The execution_table shows result assigned before printing.

Visual Quiz - 3 Questions

Look at the execution_table, what is the result of 5 <=> 10 at step 1?

A 0

B -1

C 1

D true

💡 Hint

Check the 'Result' column in execution_table row 1.

At which step is the comparison result printed?

A Step 1

B After program ends

C Step 2

D Before comparison

💡 Hint

Look at the 'Expression' column for 'puts result' in execution_table.

If we compare 10 <=> 5, what would the result be?

A 1

B 0

C -1

D nil

💡 Hint

Recall the spaceship operator returns 1 if the left is greater than the right.

Concept Snapshot

Spaceship operator (<=>) compares two values.
Returns -1 if left < right.
Returns 0 if left == right.
Returns 1 if left > right.
Useful for sorting and comparisons.
Syntax: a <=> b

Full Transcript

The spaceship operator in Ruby compares two values and returns -1, 0, or 1. It returns -1 if the first value is less than the second, 0 if they are equal, and 1 if the first is greater. For example, 5 <=> 10 returns -1 because 5 is less than 10. This result can be stored in a variable and printed. This operator is helpful when you want to know the order between two values, not just if one is true or false compared to the other.