Design Patterns · Middle · Question 47 of 75

When should you extract an abstraction, according to the "rule of three"?

✓Correct answer: When similar code shows up for the third time
2Right away, when writing the code for the first time, for the future
3Only after the project has existed for three years

Explanation

Two cases are often similar by accident, while the third shows what's truly common. The rule helps balance DRY and YAGNI.

Further reading

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