智慧职教: 阅读下面小程序，选出正确答案（）。
public class TestString {
public static void main(String[] args) {
String str = "I am a String!";
int n=str.length(); char c=str.charAt(7);
System.out.println(n);
System.out.println(c); }
}
public class TestString {
public static void main(String[] args) {
String str = "I am a String!";
int n=str.length(); char c=str.charAt(7);
System.out.println(n);
System.out.println(c); }
}
举一反三
- public class ChangeStrDemo { public static void changeStr(String str){ str="welcome"; } public static void main(String[] args) { String str="home"; changeStr(str); System.out.println(str); } }给出程序的运行结果（ ）
- 下面程序段的输出结果是 public class A{ public static void main(String args[]) { String str ="Hello,"; str=str+"Guys!"; System.out.println(str); } }
- 下列程序的运行结果是（）public class Test {public static void main(String[] args) {String str = NULL;System.out.println(str);}} A:
- 有如下代码： public class Test{ public static void main(String args[]) { String str = new String("World"); char ch[] = {'H','e','l','l','o'}; change(str,ch); System.out.println(str + "and" + ch); } public static void change(String str, char ch[]) { str = "Changed"; ch[0] = 'C'; } } 运行后输出的结果是：
- 中国大学MOOC: 下列代码中构造方法的返回类型是（）public class Village { Village () { System .out .println(“hiding in Village”) ; } public static void main( String args [ ]) { Village c =new Village ( ) ;}class Village { public static void main( String args [ ]) { Village c =new Village ( ) ; } Village () { System .out .println(“hiding in Village”) ; } }