62. Given the following incomplete method: 1) public void method(){ 2) 3) if (someTestFails()){ 4) 5) } 6) 7) } You want to make this method throw an IOException if,and only if,the method someTestFails() returns a value of true. Which changes achieve this? A. Add at line 2:IOException e; B. Add at line 4:throw e; C. Add at line 4:throw new IOException(); D. Add at line 6:throw new IOException(); E. Modify the method declaration to indicate that an object of type Exception might be thrown. 63. Given the following definition: String s = null; Which code fragments cause an object of type NullPointerException to be thrown? A. if((s!=null)&(s.length()>0)) B. if((s!=null)&&(s.length()>0)) C. if((s==null)|(s.length()==0)) D. if((s==null)||(s.length()==0))
64. The following is a program 1) class Exsuper{ 2) String name; 3) String nick_name; 4) 5) public ExSuper(String s,String t){ 6) name = s; 7) nick_name = t; 8) } 9) 10) public string toString(){ 11) return name; 12) } 13) } 14) 15) public class Example extends ExSuper{ 16) 17) public Example(String s,String t){ 18) super(s,t); 19) } 20) 21) public String to String(){ 22) return name +”a.k.a”+nick_name; 23) } 24) 25) public static void main(String args[]){ 26) ExSuper a = new ExSuper(“First”,”1st”); 27) ExSuper b = new Example(“Second”,”2nd”); 28) 29) System.out.println(“a is”+a.toString()); 30) System.out.println(“b is”+b.toString());
上一页 [1] [2] [3] [4] [5] 下一页 |