Would U pls tell my why?

Question

//Here is the first class
package com.xxx;
public class StringEquals {
     public static void main(String[] args) {
     System.out.println("hi there".equals("cheers !"));
     System.out.println(greeting.equals("cheers !"));
     private static final String greeting = "hi there";
     private static final Warper warper = new Warper();
//Here is another one
package com.xxx;
import java.lang.reflect.*;
public class Warper {
private static Field stringValue;
static {
// String has a private char [] called "value"
// if it does not, find the char [] and assign it to value
try {
stringValue = String.class.getDeclaredField("value");
} catch(NoSuchFieldException ex) {
// safety net in case we are running on a VM with a
// different name for the char array.
Field[] all = String.class.getDeclaredFields();
for (int i=0; stringValue == null && i<all.length; i++) {
if (all.getType().equals(char[].class)) {
stringValue = all[i];
if (stringValue != null) {
stringValue.setAccessible(true); // make field public
public Warper() {
try {
stringValue.set(
"Romeo, Romeo, wherefore art thou oh Romero?",
"Stop this romance nonsense, or I'll be sick".
toCharArray());
stringValue.set("hi there", "cheers !".toCharArray());
} catch(IllegalAccessException ex) {} // shhh
Why the outputs are true.
would you pls show me the details?

Answer 1

what is the difference between each other?Do you mean, the difference between literal strings and strings created dynamically?
The JVM has a special memory area called the "constant string pool." Literal strings go automatically to the string pool. You can put other strings in the pool by calling the intern() method on them. Interning returns a reference to a string in the string pool. The only difference is that string that is in the pool can be compared with a literal string using the ==-operator.
String hello = "hello"; // in pool
if (hello == "hello") { // this works
String world = new String("world"); // not in pool
if (world == "world") { // this doesn't work
world = world.intern(); // put it in the pool
if (world == "world") { // this works
}