单项选择题

A. Compilation fails.
B. An exception is thrown at runtime.
C. The variable first is set to null.
D. The variable first is set to elements[0].

相关考题

单项选择题 11. class Cup { }  12. class PoisonCup extends Cup { }  21. public void takeCup(Cup c) {  22. if(c instanceof PoisonCup) {  23. System.out.println(”Inconceivable!”);  24. } else if(c instanceof Cup) {  25. System.out.println(”Dizzying intellect!”);  26. } else {  27. System.exit(0);  28. }  29. }  And the execution of the statements:  Cup cup = new PoisonCup(); takeCup(cup);  What is the output?()

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单项选择题 public static void test(String str) { int check = 4;  if (check = str.length()) {  System.out.print(str.charAt(check -= 1) +“, “);  } else {  System.out.print(str.charAt(0) + “, “);  }  }  and the invocation:  test(”four”);  test(”tee”); test(”to”);  What is the result?()