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Why does the expression x += y *= 2; in C execute without error, and what is the order of operations?

hard📝 Conceptual Q10 of 15
C - Operators and Expressions
Why does the expression x += y *= 2; in C execute without error, and what is the order of operations?
AIt executes both simultaneously without order
BBecause '*=' executes first, then '+='; right-to-left associativity
CIt causes a syntax error due to multiple assignments
DBecause '+=' executes first, then '*='; left-to-right associativity
Step-by-Step Solution
Solution:

  1. Step 1: Understand operator associativity

    Assignment operators associate right to left, so 'y *= 2' executes first.

  2. Step 2: Apply operations in order

    First y is multiplied by 2 and assigned, then x adds the new y value and assigns.

  3. Final Answer:

    '*=' executes first, then '+=' due to right-to-left associativity -> Option B

  4. Quick Check:

    Assignment operators associate right to left [OK]
Quick Trick: Assignment operators run right to left in expressions [OK]
Common Mistakes:
  • Assuming left-to-right execution
  • Thinking it causes syntax error
  • Ignoring operator associativity

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