Given the code fragment: UnaryOperator<Double> uol = s -> s*2; //line n1 List<Double> loanValues = Arrays.asList(1000.0, 2000.0); loanValues.stream() .filter(lv -> lv >= 1500) .map(lv ->…

Question

Options

• A4000.0
• B4000
• CA compilation error occurs at line n1.
• DA compilation error occurs at line n2.

• A
  76% (25)
• B
  3% (1)
• C
  12% (4)
• D
  9% (3)

Explanation

Option A (4000.0) is correct because the stream filters [1000.0, 2000.0] down to only 2000.0 (the single value satisfying >= 1500), then maps it through uol.apply(2000.0) which computes 2000.0 * 2 = 4000.0, and forEach prints it with a trailing space - but since Double.toString(4000.0) produces "4000.0", the decimal is included in the output.

B is wrong because Java prints double/Double values with a decimal point (e.g., 4000.0, not 4000); integer-looking output would require an explicit cast or integer type.

C is wrong because line n1 is perfectly valid - UnaryOperator<Double> expects a lambda (Double) -> Double, and s -> s * 2 compiles correctly with s inferred as Double.

D is wrong because line n2 is also valid - UnaryOperator<T> extends Function<T, T>, so uol.apply(lv) satisfies Stream.map()'s requirement of a Function<Double, R>.

Memory tip: When you see a stream chain, trace the data one step at a time - filter first (what survives?), then transform (what does each element become?). Also remember: Java always prints floating-point types with a decimal, so any answer showing an integer output (4000) for a Double value is a red flag.

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