Properties of string

• **String class ： Representative string .**Java All string literals in the program （ Such as “abc” ） Are implemented as examples of this class .
• String It's a final class , representative An immutable sequence of characters .
• Strings are constants , Use double quotation marks to indicate . Their values cannot be changed after creation .
• String The character content of the object is stored in a character array value[] Medium .
• String constants are stored in String constant pool , The purpose is to share . example ：String str = “hello”;
• String non constant object stored in Pile up in . example ：String s1 = new String();

String splicing ：

• The concatenation results of constants and constants are in the constant pool . And there will be no constants with the same content in the constant pool .
• As long as one of them is a variable , The result is in the pile
• If the result of splicing calls intern() Method , The return value is in the constant pool