Java软件中级工程师笔试题复杂逻辑

1、J2EE部分1运算符优先级问题，下面代码的结果是多少？(笔试)package test;public class Test public static void main( Stri ng args) int k = 0;in t ret = +k + k+ + +k + k;/ ret的值为多少System.err.pri ntln (ret);2、运算符问题，下面代码分别输出什么？（笔试）package test; public class Test public static void main( Stri ng args) int i1 = 10, i2 = 10;System.err

2、.pri ntln( i1 + i2 = + i1 + i2);System.err.pri ntln( i1 - i2 = + i1 - i2);System.err.pri ntln( i1 * i2 = + i1 * i2);System.err.pri ntln (i1 / i2 = + i1 / i2);3、下面代码的结果是什么？还是抛出异常？(笔试) package test;public class Test public void myMethod(Stri ng str) System.err.pri ntl n(stri ng);public void myMethod(O

3、bject obj) System.err.pri ntl n(object);public static void main( Stri ng args) Test t = new Test();t.myMethod( null);4、 假设今天是9月8日，下面代码输出什么？(笔试)package test;import java.util.Date;public class Test public static void main( Stri ng args) Date date = new Date();System.err.pri ntln( date.getMo nth() + +

4、date.getDate();5、下面代码的输出结果是什么？package test;public class Test public static void main( Stri ng args) double val = 11.5;System.err.pri ntln (Math.ro un d(val);System.err.pri ntln (Math.floor(val);System.err.pri ntl n( Math.ceil(val);6、下面代码的结果是什么？package test;public class Test exte nds Base public stat

5、ic void main( Stri ng args) Base b = new Test();b.method();Test t = new Test();t.method();Overridepublic void method() System.err.pri ntl n(test);class Base public void method() throws InterruptedException System.err.pri ntln (base);7、以下代码的结果是什么？package test;public class Test exte nds Base public st

6、atic void main( Stri ng args) new Test().method();public void method() System.err.pri ntl n(super.getClass().getName();System.err.pri ntl n(this.getClass().getSuperclass().getName(); class Base 8、true or false ?package test;public class Test public static void main( Stri ng args) String str1 = new S

7、tring(abc);Stri ng str2 = new Strin g(abc);System.err.pri ntln (str1.equals(str2);Str in gBuffer sb1 = new Strin gBuffer(abc);Stri ngBuffer sb2 = new Stri ngBuffer(abc); System.err.pri ntl n( sb1.equals(sb2);9、输出的结果是什么？package test;public class Test public static void main( Stri ng args) System.err.

8、pri ntl n(new Test().method1();System.err.pri ntl n(new Test().method2();public int method1() int x = 1;try return x; fin ally +x;public int method2() int x = 1;try return x; fin ally retur n +x;这样呢？输出什么package test;public class Test public static void main( Stri ng args) System.err.pri ntl n(method

9、();public static boolea n method() try return true; fin ally return false;10、方法m和m2有区别吗？什么区别package test;public class Test public static void main( Stri ng args) public syn chr oni zed void m1() public static synchroni zed void m2() 11、true or false ?理由 package test;public class Test public static v

10、oid main( Stri ng args) In teger i1 = 127;In teger i2 = 127;System.err.pri ntl n(i1 = i2);11 = 128;12 = 128;System.err.pri ntl n(i1 = i2);12、true or false ?理由package test;public class Test public static void main( Stri ng args) String str1 = a;String str2 = a;String str3 = new String(a);System.err.p

11、ri ntl n(str1 = str2);System.err.pri ntl n(str1 = str3);str3 = str3.i ntern();System.err.pri ntl n(str1 = str3);13、true or false ?理由package test;public class Test public static void main( Stri ng args) System.err.println(12 - 11.9 = 0.1);14、以下代码输出是什么?package test;import java.math.Bigl nteger;public

12、class Test public static void main( Stri ng args) BigInteger one = new BigInteger(1);BigI nteger two = new BigI nteger(2);BigI nteger three = new BigI nteger(3);BigI nteger sum = new BigI nteger(O); sum.add( on e);sum.add(two);sum.add(three);System.out.pr intln( sum.toStri ng();15、输出的结果是什么？12345?根据单

13、词排序？还是？package test;import java.util.HashSet;import java.util.Iterator;import java.util.Set;public class Test public static void main( Stri ng args) SetvStr ing set = new HashSetvStri ng(); set.add(o ne);set.add(two); set.add(three);set.add(four); set.add(five);for (IteratorvStri ng it = set.iterato

14、r(); it.hasNext();) System.err.pri ntln (it .n ext();16、以下代码输出的结果（笔试选择题）word资料public class Test public static void main( Stri ng args) System.err.pri ntl n( args .len gth);A. nullB. 0C. TestD. Exception in thread main java.lang.NullPointerException17、下面为一个单例的实现代码，请指出代码中有几个错误或不合理之处，并改正。public class T

15、est public Test in sta nee = n ull;public static Test get In sta nce() if (in sta nee = n ull) in sta nee = new Test(); retur n in sta nee;tab。（笔试）18、编程输出一个目录下的所有目录及文件名称，目录之间用19、 从键盘读入10个整数，然后从大到小输出。（笔试）20、如何迭代 Map容器，手写个试试？答案:1、2、8i1 + i2 = 1010 语法错误i1 * i2 = 100i1 / i2 = 13、4、stri ng5195、6、12test11

16、.0test12.07、8、test.Testtruetest.Basefalse9、10、1A: synchronized static是某个类的范围，2synchronized static cSync防止多个线程同false时访冋这个类中的 synchronized static方法。它可以对类的所有对象实例起作用。B: synchroni zed是某实例的范围，synchroni zed isSy nc()防止多个线程同时访问这个实例中的synchronized方法。11、12、truetruefalsefalsetrue13、14、false015、16、twoBfiveonethr

17、eefour17、get In sta nee无默认返回值in sta nee必须是 static18package test; import java.io.File; public class Test public static void main( Stri ng args) new Test().read(D:/test, );public void read(Stri ng path, String tab) File file = new File(path); File childFiles = fileistFiles();for (int i = 0; childFiles

18、 != null & i childFiles.length; i+) System.err.pri ntl n(tab + childFilesi.getName();if (childFilesi.isDirectory() read(childFilesi.getPath(), tab + t);19、package test;import java.util.Arrays;import java.util.Comparator;import java.util.Sca nn er; public class Test public static void main( Stri ng args) Scanner in = new Sca nn er(System.i n);/注意这里的数组，不是int的In teger arr = new In teger10; for (i nt i = 0; i () Override public int compare(l nteger o1, In teger o2) if (o1 o2) return -1;if (o1