String 类的intern方法_string类型的intern方法-优快云博客

 
  public static void main(String[] args) {  
         String s = new String("abc");  
         String b = s.intern();  
         if (s == b) {  
             System.out.println("字符串abc在常量池中");  
         } else {  
             System.out.println("字符串abc不在常量池中");  
         }  
   
         String s1 = "abc";  
         String b1 = s1.intern();  
         if (s1 == b1) {  
             System.out.println("字符串abc在常量池中");  
         } else {  
             System.out.println("字符串abc不在常量池中");  
         }  
     }  
 

结果：
字符串abc不在常量池中
字符串abc在常量池中

详见jdk
public native String intern();

if the pool already contains a string equal to this String object,
then the string from the pool is returned. Otherwise, this String object is added to the pool and a reference to this String object is returned.
说明b和b1都是来自pool的。而new的Object是动态heap上的，这也从侧面证明了
String s = new String("123");创建几个对象的原理