杭州天丽科技有限公司 面试 笔试题.docVIP

选择题 1: What?will?happen?when?you?attempt?to?compile?and?run?the?following?code?? ?? ?? class?Base? ?? ?? { ?? ?? int?i?=?99;? ?? ?? public?void?amethod() ?? ?? { ?? ?? ???????System.out.println(Base.amethod()); ?? ?? ?????} ?? ?? ?????Base() ?? ?? { ?? ?? ?????amethod(); ?? ?? ?????} ?? ?? }? ?? ?? public?class?Derived?extends?Base ?? ?? { ?? ?? int?i?=?-1; ?? ?? ??????? ?? ?? public?static?void?main(String?argv[]) ?? ?? { ?? ?? ?????Base?b?=?new?Derived(); ?? ?? ???????System.out.println(b.i); ?? ?? ???????b.amethod(); ?? ?? ?????}? ?? ?? ?????public?void?amethod() ?? ?? { ?? ?? ???????System.out.println(Derived.amethod()); ?? ?? ?????}? ?? ?? }? ?? ?? Choices:?? What will happen when you attempt to compile and run the following code? class Base { int i = 99; public void amethod() { System.out.println(Base.amethod()); } Base() { amethod(); } } public class Derived extends Base { int i = -1; public static void main(String argv[]) { Base b = new Derived(); System.out.println(b.i); b.amethod(); } public void amethod() { System.out.println(Derived.amethod()); } } Choices: A.Derived.amethod() -1 Derived.amethod() B.Derived.amethod() 99 C.Compile time error D.Derived.amethod() 2:使用 JDBC 可以做到的是 A.把二进制代码传送到任何关系数据库中 B.把 Java 源代码传送到任何关系数据库中 C.把表单信息传送到任何关系数据库中 D.很容易地把 SQL 语句传送到任何关系数据库中 3: String?s=”Example?String”;Which?operation?is?not?legal??? String s=”Example String”;Which operation is not legal? A.int i=s.length(); B.s[3]=”x”; C.String short_s=s.trim(); D.String t=”root”+s; 4: public?class?X{ ?? ?? ???public?Object?m(){ ?? ?? ??????Object?o?=?new?Float(3.14F);//line?3 ?? ?? ??????Object?[]?oa?=?new?Object[1];//line?4 ?? ?? ??????oa[0]?=?o;//line?5 ?? ?? ??????o=null;//line?6 ?? ?? ??????return?oa[0];//line?7 ?? ?? ?????} ?? ?? } ?? When?is?the?Float?object,?created?in?line?3,eligible?for?garbage?collection??? public class X{ public Object m(){ Object o = new Float