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...
String is widely used as parameter for many java classes, e.g. network connection, opening files, etc. Were String not immutable, a connection or file would be changed and lead to serious security threat. The method thought it was connecting to one machine, but was not. Mutable strings cou...
System.exit(1); return null; } } static char[] decode(byte[] ba, int off, int len){ String csn = Charset.defaultCharset().name(); try{ //use char set name decode() variant which provide scaching. return decode(csn, ba, off, len); } catch(UnsupportedEncodingException x){ warnUn...
(@"%@" , mstr); 49 50 //替换一些字符 51 [mstr replaceCharactersInRange:NSMakeRange(8, 6) withString:@" a mutable string"]; 52 NSLog(@"%@" , mstr); 53 54 //查找和替换 55 search = @"this is"; 56 replace = @"an example of"; 57 58 substr = [mstr rangeOfString:search]; ...
StringBuffer is mutable and thread safety as all the methods of this class are synchronized, so we should prefer to use it in multithreaded application StringBuilder is mutable but not thread safe as methods of this class are not synchronized, so we should prefer to use it in single ...
StringBufferandStringBuilderare mutable classes.StringBufferoperations are thread-safe and synchronized, whileStringBuilderoperations are not thread-safe. You should useStringBufferin a multi-threaded environment and useStringBuilderin a single-threaded environment.StringBuilderperformance is faster thanStringBuffer...
我们先来说说,java中八大数据类型,然后在说String。 八大基本数据类型 byte:8位,最大存储数据量是255,存放的数据范围是-128~127之间。 short:16位,最大数据存储量是65536,数据范围是-32768~32767之间。 int:32位,最大数据存储容量是2的32次方减1,数据范围是负的2的31次方到正的2的31次方减1。 long:64位,...
All string literals in Java programs, such as "abc", are implemented as instances of this class. 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. For example: String ...
* A mutable sequence of characters. This class provides an API compatible * with {@code StringBuffer}, but with no guarantee of synchronization. * This class is designed for use as a drop-in replacement for * {@code StringBuffer} in places where the string buffer was being ...
java编程中的所有字符串常量。 * 比如说:"abc"就是这个String类的实例 * * Strings are constant; their values cannot be changed after they * are created. * 字符串是常量,他们一旦被创建后,他们的值是不能被修改。(重点) * String buffers support mutable strings. * String缓存池支持可变的字符串, ...