多选题

Given the following code, which of th...

Question

Given the following code, which of the statement(s) is(are) true?

import java.util.HashMap
import java.util.Map

public class Foo {  public static void main(String[] args) {  Map<String, Integer> map = new HashMap<String, Integer>() // 1  map.put("a", 127) // 2  map.put("b", new Integer(127)) // 3  map.put(null, null) // 4  System.out.println(map.get("a") == (map.get("b"))) // 5  }
}

A. Compilation error at line //2

B. Compilation error at line //4

C. Runtime exception at line //4

D. Code can run through with "true" as output.

E. None of the above is correct.