String construction method and character set encoding conversion

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String construction method and character set encoding conversion

String (): new string () generates "" empty string object, not null,null not pointing to memory;
String (java.lang.String): New String ("AAA"), each time creating a memory storage string;
String (char[]): char[] ch={' A ', ' B ', ' C '},new string (CH) converts the character array to the string "ABC";
String (byte[], java.lang.String): Parameter 1 is a byte[] byte array, parameter 2 String is a character set, such as "GBK", "UTF-8", Examples:

Casts a byte array into a set of character sets;
String (byte[]): Converts a byte array into a string by the system default character set encoding format;
GetBytes (): Converts a string to a byte array by the system's default character set, example:

GetBytes (java.lang.String): Install the passed-in character set for conversion, example:

Length (): Returns the length of the string (by the number of characters);
IsEmpty (): Judging is not an empty string "", is the return true, not to return false, not to judge Null;
Trim (): Remove left and right spaces (middle space cannot be removed);
toLowerCase (): string turns lowercase;
toUpperCase (): string to uppercase;
Split (java.lang.String): separates by specific characters, returns an array of strings, examples:

indexOf (int): Finds the first occurrence in a string by the given character, and returns the subscript number of type int;
IndexOf (java.lang.String): Find the place where the string first appears, example:

LastIndexOf (String): Find the first occurrence of a string from behind, example:

IndexOf (java.lang.String, int): Set an index to start the search to find the string, return the position of the subscript where the string appears, example:

charAt (int): Returns the character according to the given subscript, example:

substring (int, int): Intercepts a string, parameter 1 is the subscript to start intercepting, parameter 2 is the subscript to end the interception, example:

SUBSTRING (int): From the given start subscript backward interception, example:

StartsWith (java.lang.String): Determines the string prefix, returns a Boolean value, example:

EndsWith (String): determines the string suffix;
Equals (String): Determines whether the contents of two string objects are the same, returns a Boolean value, example:

Replace (Oldchar,newchar): Replacement character, example:

Replace (Java.lang.CharSequence, java.lang.CharSequence): replacement string, Parameter 1 is the old string, that is, the replaced string; parameter 2 is a new string, example:

ReplaceAll Replace all, you need to use regular expressions,

String construction method and character set encoding conversion