【java】intern步骤实践

【java】intern方法实践
今天心血来潮，看了看java笔试题，其中有人提到intern的方法，我暂且测试一番。

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

查看更多 下一篇