Java 底层知识 --- 内存模型之常见考题

你的名字 2022-02-05 11:43 245阅读 0赞

内存模型之常见考题

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问题一：不同JDK 版本直接intern () 方法的区别 - JDK6 JDK VS JDK6+   ?

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选择Edit Configurations... ,并且选择需要运行的当前类

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此异常出现是在JDK 6

JDK 6+ 就不会出现 ，字符串常量池，不受永久带限制

JDK 7 可以正常执行

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JDK 8 可以正常执行，但是提示

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== 比较的内存地址

一、

String s = new String ("a");

s.intern();

String s2 = "a";

System.out.print(s == s2);

二、

String s3 = new String("a")+new String("a");

s3.intern();

String s4 = "aa"';

System.out.print(s3 == s4);

当JDK版本 高于6 时 结果是：一、输出 false 二、输出true

当JDK版本 为6 时 结果是：一、输出 false 二、输出false

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