A commonly used method of String Class
. 1 . 1 . Get: 2 . 1 ) acquires a length of string str . 3 int I = str.length (); . 4 2 ) acquires the character based on the position (index) . 5 char C = str.charAt (index); . 6 . 3 ) acquired character string position . 7 int I = str.indexOf ( char CH); // Get the position of the first occurrence . 8 int I = str.indexOf ( char CH, int index); // Get the position index from the first occurrence of a position ch . 9 int I = str.indexOf (str1); // Get position str1 str first appears at 10 int I = str.indexOf (str1, index0); // Get position from the index position of the first occurrence of str . 11 int I = str.lastIndexOf (ch or str1) // position acquisition ch str1 last seen or 12 is 13 is 2 . Analyzing 14 . 1 ) determines whether to start with the specified string str1, the end of the 15 Boolean B = str.startWith (str1) // beginning 16 Boolean B = str.endsWith (str1) // end . 17 2 ) comprises determining whether a sub-string 18 is Boolean B = str.contains (str1) . 19 . 3 ) determines whether the content string 20 is Boolean B =str.isEmpty (); 21 is . 4 ) determines whether the character string identical to ignore case 22 is Boolean B = str.equalsIgnoreCase (str1); 23 is 24 . 3 . converters 25 1) character array - char [] CH-, converted into a string 26 string STR = I. new new string (CH); // the whole array into a string 27 II string = STR. new new string (CH, offset, count) 28 // the count number of elements after the offset location of the character array into a string 29 1. string STR = String.valueOf (CH); 30 2. string STR =String.copyValueOf (CH, offset, COUNT); 31 is 3. String STR = String.copyValueOf (CH); 32 2 ) is converted to a character string array 33 is char [] = CH str.toCharAarray (); 34 is . 3 ) The byte array into a string 35 above 1) incoming type to byte []; 36 . 4 ) to convert the string into a byte array 37 [ byte [] B = str.toByteArray (); 38 is . 5 ) the basic data types attached to a string 39 string STR = String.valueOf (basic data types); 40 if the character string data may be shaped connector + "" 41 is EG: string = 5+ STR ""; 42 to obtain the string "5 " 43 is 44 is . 4 . Alternatively Replace (); 45 str.replace (oldChar, newChar) // str to changes in oldChar newChar 46 is str.replace (str1, str2) // in str str1 , becomes str2 47 48 . 5 . cutting split (); 49 String [] str.split str1 = ( ""); // str to use "," String is divided into an array of 50 51 is . 6 . substring 52 is String S = str.substring (begin); 53 is // S str in position to begin from the last string 54 is string S =str.substring (begin, end) 55 // S str is the string end from the position to begin location 56 is 57 is . 7 to change the case:. 58 . the toUpperCase String str = S1 (); // str to capitalize letters 59 S2 = the toLowerCase str String ();. // str to lowercase letters 60 removed space: 61 is String S = str.trim (); 62 is comparison: 63 is int I = str.compareTo (str1);
Two, StringBuffer common method
. 1 / ** * the StringBuffer container is a variable length, the string can be directly manipulated, using the method becomes toString string * * / 2 . 1 storage. . 3 . 1) the append (); // the specified data is added to the end of the container The return value is the StringBuffer . 4 EG: . 5 the StringBuffer SB = new new the StringBuffer ( // can be added STR); . 6 the StringBuffer SB1 = ab.append (data) // data may be any type of data base 7 Note: At this point == SB SB1 them the same object, meaning that the new sb1 can not directly sb.append (data) after the bonding used when using sb . 8 2) iNSERT (); // insertion . 9 sb.insert (index, data); 10 2 . remove 11 sb.delete (start, end); // delete the contents of the character start end of 12 // NOTE: All operations are contained herein index containing free end of the head 13 is sb.deleteCharAt (index); // delete the specified the character position 14 // empty StringBuffer buffer 15 SB = new new StringBuffer (); 16 sb.delete (0 , sb.length ()); . 17 . 3 . Gets 18 is char C = sb.charAt (index); // Get characters on the index . 19 int I = sb.indexOf ( char ): // get char character appears first position 20 // and methods consistent String Gets the front reference 21 22 is . 4 . No modification operations String class method 23 is SB = sb.replace (start, end, String) // will begin to start end of the replacement string String; 24 sb.setCharAr (index, char ); / / character becomes the new index position char 25 26 is 5. the inversion sb.reverse (); // the reverse sb 27 6. the getChars ( int the srcBegin, int the srcEnd, char [] CH, int chBegin) 28 // the StringBuffer buffer specified data is stored into the specified array
Three, StringBuilder StringBuilder and StringBuffer methods and functions exactly the same just an early version (StringBuffer) are thread-safe, the discovery of the utilization of the same multi-threaded heap String data manipulation is very small, in order to improve efficiency in the future idk1.5 have StringBuilder class. Meaning is multi-threaded operating time with the same string StringBuffer security, are now generally used StringBuilder
Reference: https://blog.csdn.net/qq_34107571/article/details/80098055