Which of the following sentence is right in G major ? A: An open inner string counts as 2, the outer string counts as 5 B: An open inner string counts as 5, the outer string counts as 2 C: An open inner string counts as 2, the outer string counts as 6 D: An open inner string counts as 6, the outer string counts as 3

下列【1】【2】【3】【4】注释标注的哪行代码有错误？import java.util.*;public class E {public static void main(String args&#91;&#93;) {Map<;String,String>; map = new HashMap<;String,String>;(); //【1】Set<;Integer>; treeSet = new TreeSet<;Integer>;();//【2】Map<;String,String>; treeMap= new TreeMap<;String,String>;(); //【3】List<;char>; list = new LinkedList<;char>;(); //【4】 A: 【1】 B: 【2】 C: 【3】 D: 【4】

以下代码共创建了几个对象？String s1=new String("hello");String s2=new String("hello");String s3=s1;String s4=s2; A: 2 B: 4 C: 1 D: 3

$string="A";$string=$string x 4;$string.="B";$string.="A";$find_B=index($string,"B");执行以上语句后，$find_B=？ A: 4 B: 3 C: 2 D: 1

设字符串变量String name1="tommy", String name 2=new String("tommy ")，则以下表达式的值为true的是（）

以下程序的输出结果是 String s1="1",s2="2"; String s=s1+s2; System.out.println(s);

执行下面代码后，将创建（）个对象。String s1="hello";String s2=new String(s1); A: 0 B: 1 C: 2 D: 3

执行语句string str=＂2＂＋2；后str的值是

public static void main(String[] args) { LinkedList list=new LinkedList(); list.add("A"); list.add("B"); String s=(String)list.get(2); System.out.println(s); } 编译运行的结果是

下列语句存在语法错误的是（      ） A: vara[]inta=append(a,9) B: varmmap[string]intm[“a”]=5 C: varmmap[string]intm=make(map[string]int)m[“a”]=5 D: vara=[][2]int{{0,0},{1,2},{2},{3,6},{4,8}}