试题如下:
参考答案:
导入java.io.io.filenotfoundException; import java.io.ioexception; import java.util.arraylist; import java.util.concurrent.concurrent.executorservice; import java.util.util.util.concurrent.executors; executors;/**由ysc在7/26/16/16/16/16/26/16/ysc上创建。 */公共类采访{private static void One(){字符串str1 =“ Hello”;字符串str2 =“ he”+new String(“ llo”); system.err.println(str1 == str2); system.out.println(“1。false”); } private static void二(){int i = integer.max_value; system.err.println(((i+1)<i); system.out.println(“ 2。存在一个i,使得(i+1)<i”); } private static void三(){system.err.println(“ GC不是Java线程,它是本机线程”); thread.getAllStackTraces()。keyset()。foreach(thread-> system.out.println(thread.getName()+“ - >” - >“ - >”+thread.isdaemon()+“”+thread.getPriority()); system.out.println(“3。Gc线程是守护程序线程”); }私有静态挥发性int count = 0; private static void四(){executorService executorService = executors.newcachedthreadpool(); for(int j = 0; j <10; j ++){executorService.Submit(() - > {for(int i = 0; i <1000000; i ++){count ++;}}); } system.out.println(“计数应为:“ +10000000+”,实际be:“+count); system.out.println(“ 4。挥发性不能保证线程安全”); } private static void fix(){arrayList <integer> list = new ArrayList <>(20); list.add(1); system.out.println(“调试代码,而不是执行grow方法”); system.out.println(“ 5。列表增长0次”); } private static void六(){system.out.println(“ BufferedReader的构造函数仅接受读取器实例”); system.out.println(“6。NewBufferedReader)(new FileInputStream(/“ a.dat/”));是错误的); } private static void七(){try {if(true){thur new ioexception(); }} catch(filenotfoundException e){system.out.print(“ filenotfoundexception!”); } catch(ioexception e){system.out.print(“ ioexception!”); } catch(异常E){system.out.print(“ exception!”); } system.out.println(“/n7。ioexception!”); } private static void八(){system.out.println(“字符串s; system.out.println(s);错误:变量s可能没有用-xlint初始化/nrecompile,以-xlint:未经检查以获取详细信息。”); system.out.println(“ 8。 } private static void nine(){system.out.println(“ 5” +2); system.out.println(“9。52”); }私有静态void ten(){int i = 2; int结果= 0;开关(i){情况1:结果=结果 + i;案例2:结果=结果 + i * 2;案例3:结果=结果 + i * 3; } system.out.println(“结果=”+结果); System.out.println(“10。10”); }私有静态类NULL {public static void Hello(){System.out.println(“ Hello”); } public static void main(string [] args){(((null)null).hello(); null _null =(null)null; _null.hello(); }}私有静态类StringExample1 {字符串str = new String(“ good”); char [] ch = {'a','b','c'}; public void Change(String str,char [] ch){str =“ test ok”; ch [0] ='g'; } public static void main(string [] args){StringExample1 ex = new StringExample1(); ex.Change(ex.str,ex.ch); system.out.print(ex.str+“ and”); system.out.print(ex.ch); system.out.println(); }} private static class stringexample2 {public static void change(string str){str =“欢迎”; } public static void main(string [] args){string str =“ 1234”;更改(str); system.out.println(str); }} private static类forloop {static boolean foo(char c){system.out.print(c);返回true; } public static void main(string [] args){int i = 0; for(foo('a'); foo('b')&&(i <2); foo('c')){i ++;食物'); } system.out.println(); }} private static类helloa {public helloa(){system.out.println(“ helloa”); } {system.out.println(“我是class”); } static {system.out.println(“ static a”); }} private static类Hellob扩展了Helloa {public HellOb(){System.out.println(“ HellOb”); } {system.out.println(“我是B class”); } static {system.out.println(“ static b”); } public static void main(string [] args){system.out.println(“ main start”); new Hellob(); new Hellob(); System.out.println(“ Main End”); }} public static void main(string [] args){一();二();三();四();五();六();七();八();九();十(); null.main(null); StringExample1.main(null); StringExample2.2.main(null); forloop.main(null); hellob.main(null); }}}以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武林网。,也希望大家多多支持武林网。