单项选择题
A. The code compiles and “s=” is printed.
B. The code compiles and “s=null” is printed.
C. The code does not compile because string s is not initialized.
D. The code does not compile because string s cannot be referenced.
E. The code compiles， but a NullPointerException is thrown when toString is called.
多项选择题 public interface Foo{ int k = 4； } Which three are equivalent to line 2？（）
单项选择题 int index = 1； String [] test = new String[3]； String foo = test[index]； What is the result？（）
单项选择题 public class Test { public static void main （String[]args） { String foo = args[1]； String bar = args[2]； String baz = args[3]； System.out.printIn（“baz = ” + baz）； } } And the output： Baz = 2 Which command line invocation will produce the output？（）