Union: Combining Sets

Concepts covered: pySetOperations

A union combines all elements from two or more sets into a single set. If an element appears in any of the input sets, it appears in the union exactly once. The union operation automatically handles duplicates because the result is still a set, which by definition contains only unique elements. This makes union perfect for merging data from multiple sources. The mathematical notation for union is A ∪ B, read as "A union B". The union of sets A and B contains every element that is in A, in B, or in both. The key insight is that union is an inclusive operation: if you are in either set, you are in the result. This is analogous to the logical OR operation: an element is in the union if it is in A OR in B OR in both. Notice that "javascript" appears in both the frontend and backend sets but on

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