Given the code fragment: 5. float fValue = 120; 6. int iValue = fValue; 7. double dValue = fValue; 8. long lValue = fValue; At which line does a compilation error occur?

Question

Options

• Alines 5 and 7
• Bline 7
• Clines 6 and 8
• Dline 5

• A
  4% (3)
• B
  1% (1)
• C
  9% (6)
• D
  86% (59)

Explanation

The provided answer key appears to be incorrect. Option C (lines 6 and 8) is the actual correct answer based on Java's type conversion rules. Here's the full breakdown:

Why lines 6 and 8 fail:

• int iValue = fValue; - assigning float to int is a narrowing conversion (float → int loses the fractional part and possibly magnitude). Java requires an explicit cast: int iValue = (int) fValue;
• long lValue = fValue; - same issue. Even though long has more bits, float → long is still a narrowing conversion in Java's type hierarchy. An explicit cast is required.

Why lines 5 and 7 are fine:

• float fValue = 120; - 120 is an int literal. int → float is a widening conversion and is allowed implicitly. No error here.
• double dValue = fValue; - float → double is also widening. Perfectly legal with no cast needed.

Java's widening order to memorize:

byte → short → int → long → float → double

Assignments going left to right (widening) are implicit. Going right to left (narrowing) requires an explicit cast.

Memory tip: "Wide is fine, narrow needs a sign" - widening is silent, narrowing needs a visible (cast) to remind you data may be lost.

If this question came from a practice exam or textbook, the answer key has a typo - C is correct.

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