Question

java程序,假设s1,s2,s3和s4是四个字符串引用,分别对它们进行如下赋值：

Answer 1

public class Test {

public static void main(String[] args) {

String s1="Welcome to java";

String s2=s1;

String s3=new String("Welcome to java");

String s4=s3.intern();

System.out.println("s1=s2:" + (s1==s2));

System.out.println("s2=s3:" + (s2==s3));

System.out.println("s1.equals（s2）:" + s1.equals(s2));

System.out.println("s2.equals（s3）:" + s2.equals(s3));

System.out.println("s1.compareTo（s2）:" + s1.compareTo(s2));

System.out.println("s2.compareTo（s3） :" + s2.compareTo(s3));

System.out.println("s1==s4:" + (s1==s4));

System.out.println("s1.charAt(0) :" + s1.charAt(0) );

System.out.println("s1.indexOf('j'):" + s1.indexOf('j'));

System.out.println("s1.indexOf('to'):" + s1.indexOf("to"));

System.out.println("s1.lastindexOf('j') :" + s1.lastIndexOf("j"));

System.out.println("s1.lastindexOf("o",15):" + s1.lastIndexOf("o",15));

System.out.println("s1.length():" + s1.length());

System.out.println("s1.subString(5):" + s1.substring(5));

System.out.println("s1.SubString(5,11):" + s1.substring(5,11));

System.out.println("s1.startsWith("wel"):" + s1.startsWith("wel"));

System.out.println("s1.endsWith("java"):" + s1.endsWith("java"));

System.out.println("s1.toLowerCase():" + s1.toLowerCase());

System.out.println("s1.toUpperCase():" + s1.toUpperCase());

System.out.println("" Welcome ".trim():" + " Welcome ".trim());

System.out.println("s1.replace('o','T'):" + s1.replace('o','T'));

System.out.println("s1.replaceAll("o","T"):" + s1.replaceAll("o","T"));

System.out.println("s1.replaceFirst("o","T"):" + s1.replaceFirst("o","T"));

System.out.println("s1.toCharArray():" + s1.toCharArray());

}

}