Java String Class

One, the String class

1, the string is a special object.
2. Once the string is initialized, it cannot be changed.

The String class represents a string and cannot be replicated because it has no subclasses.

Demo:

1  PackageCom.hpioneer.Demo;2 3 /**4 * @Description: String class5 * @Author: Hpioneer6 * @CreateTime: 2018/5/7 11:137 * @File: Java_string of Javaproject in Com.hpioneer.Demo8 * @FullFileName: com.hpioneer.Demo.Java_String9 * @Create by IntelliJTen * @Version: 1.0 One  */ A  Public classdemo_string{ -      Public Static voidMain (string[] args) { -  the         //character array to string -         Char[] Array = {' R ', ' U ', ' n ', ' o ', ' o ', ' B '}; -String string =NewString (Array); - System.out.println (string); +System.out.println (String.Length ());//length -System.out.println ("1, Hello,". Concat (string));//Stitching +System.out.println (", Hello," + string);//Stitching ASystem.out.printf ("The value of the floating-point variable is" + "%f, the value of the integer variable is" + "%d, the value of the string variable is" + "is%s", 1.0, 1, "1.0");//Formatting at System.out.println (); -  -String q = "a"; -String w = "B"; -String e = q +W; -String r =NewStringBuffer (). Append (q). Append (W). ToString ();//the implementation of the string addition is the append after buffer is in  -String a = "Saff"; toString B = "Saff"; +String C =NewString ("Saff"); -System.out.println (A.equals (b));//true theSystem.out.println (A.equals (c));//true *     } $ Panax Notoginseng}

Second, StringBuffer class

Demo:

1  PackageCom.hpioneer.Demo;2 3 /**4 * @Description:5 * @Author: Hpioneer6 * @CreateTime: 2018/5/7 11:587 * @File: Demo_stringbuffer of Javaproject in Com.hpioneer.Demo8 * @FullFileName: Com.hpioneer.Demo.Demo_StringBuffer9 * @Create by IntelliJTen * @Version: 1.0 One  */ A  Public classDemo_stringbuffer { -      Public Static voidMain (string[] args) { -  the        /*StringBuffer s = new StringBuffer (); - System.out.println (S.length ());//0 - System.out.println (S.capacity ());//16 Initial capacity -  + stringbuffer S1 = new StringBuffer (ten); - System.out.println (S1.length ());//0 + System.out.println (S1.capacity ());//10 A  at stringbuffer s2 = new StringBuffer ("Asas"); - System.out.println (S2.length ());//8 - System.out.println (S2.capacity ());//24 = 8+16 -  - System.out.println (S2.append (true));//asastrue - S2.deletecharat (0); in S2.delete (0,3); - System.out.println (S2.append ("DFDFDF"));//TRUEDFDFDF to System.out.println (S2.append ());//truedfdfdf100 + System.out.println (S2.insert (4, "KK"));//truekkdfdfdf100 - System.out.println (S2.reverse ());//001fdfdfdkkeurt the System.out.println (S2.replace (0,2, "111"));//1111fdfdfdkkeurt * System.out.println (s2.substring (2,5));//11f*/ $ Panax Notoginseng         /*stringbuffer sb = new StringBuffer ("Heima"); -  the string S1 = new string (SB); Convert StringBuffer to string by construction + System.out.println (S1); A  the String s2 = sb.tostring (); Convert StringBuffer to string using the ToString method + System.out.println (S2); -  $ String s3 = sb.substring (0, Sb.length ()); Converts a stringbuffer to a string by intercepting substrings $ System.out.println (S3);*/ -  -String s = "Heima"; the System.out.println (s); - Change (s);Wuyi System.out.println (s); the         //System.out.println (s+= "ITCA"); -System.out.println ("---------------------"); WuStringBuffer SB =NewStringBuffer (); -Sb.append ("Heima"); About System.out.println (SB); $ Change (SB); - System.out.println (SB); -  -          A     } +  the     Public Static voidChange (StringBuffer sb) { -Sb.append ("Itcast"); $     } the  the      Public Static voidChange (String s) { thes + = "Itcast"; the     } -      in}

Java String Class