因为缓存字符串对性能来说至关重要,因此为了移除这种风险,String被设计成Immutable。 HashMap的需要 HashMap在Java里太重要了,而它的key通常是String类型的。如果String是mutable,那么修改属性后,其hashcode也将改变。这样导致在HashMap中找不到原来的value。 多线程中需要 string的subString方法如下: 代码语言:javascript...
那么你的StringChilld就有可能是被复写为mutable的，这样就打破了成为共识的基本约定。举...
In the above example, only one object is created and that is pointed to an original string and whenever we are performing any changes in an existing object then changes will not get reflected. It means we will get result "Preeti". Java string is mutable or immutable? In Java, the string...
1. String 源码中注释 *Strings are constant; their values cannot be changed after they*are created. String buffers support mutable strings.* Because String objects are immutable they can be shared. *字符串是常量;它们的值在创建后不能更改,因为String对象是不可变的,所以它们可以共享。 publicfinalclass...
The term "Mutable" signifies the ability of an object to be modified or altered, while "Immutable" denotes the inability of an object to undergo changes. An Immutable Object, therefore, refers to an object whose state remains unaltered after its creation. ...
String in a class it is used to holding the array of characters. The difference between String and StringBuffer is String is immutable where as StringBuffer is mutable. Means we can not change the value of the string. Why it so?
On the other hand, mutableStringswould produce two different hashcodes at the time of insertion and retrieval if contents ofStringwas modified after the operation, potentially losing the value object in theMap. 3.5. Performance As we saw previously,Stringpool exists becauseStringsare immutable. In ...
has the same memory position. With this you don't waste memory declaring the same object multiple times. Because of a string is defined in many places if there was mutable a change to one will cause a change in the others, and no ones want that. That's why the strings...
Since Strings are very popular as HashMap key, it's important for them to be immutable so that they can retrieve the value object which was stored in HashMap. SinceHashMap works in the principle of hashing, which requires same has value to function properly. Mutable String would produce two...
(重点) * String buffers support mutable strings. * String缓存池支持可变的字符串, * Because String objects are immutable they can be shared. For example: * 因为String字符串不可变,但他们可以被共享。比如: * <blockquote> * String str = "abc"; * </blockquote> * is equivalent to: * ...