A detailed description of string encoding and string methods in JavaScript

The string in JS is an array of classes, using the UTF-16 encoded Unicode character set, which means that each character of the string can be obtained by subscript, and each string is a sequence of 16-bit values in memory. JS operations on strings are performed on 16-bit values, not characters.

In JS, the first character after "\" will not be resolved to a character, which is the escape character of JS:

\o         nul character \b         backspace \ t          horizontal tab \ n         newline character \v         vertical tab \f          page break \ r          carriage return \ "          double quotation mark \"            Apostrophe or single quote \ \           Backslash \xxx The Latin-1 character         specified by the two-digit hexadecimal number xx\uxxxx the         Unicode character specified by the four-bit hexadecimal number xxxx 

    var str= "Pomelott is good\nyes he's!" ;    Console.log (STR1);

The console output is as follows:

!

JS Common String Method usage explained:

    varS= "Hellow,pomelott"; Console.log (S.charat (0));//hConsole.log (S.charat (s.length-1));//T    //substring (start, end)    //1. Starting from subscript 1 (including) to subscript 4 end (not included)    //2. SUBSTRING () parameter does not support negative numbersConsole.log (s.substring (1,4));//"ell"    ///slice (Start, end)    //1. If the starting digit is negative, start from the countdown;    //2. End bit number optional, default means cut from start to end of stringConsole.log (S.slice (1,4));//"ell"Console.log (S.slice (-3));//"Ott"    //s.indexof ("x") x the first occurrence of the position, does not exist then returns-1Console.log (S.indexof ("L"));//2Console.log (S.indexof ("z"));//-1Console.log (S.indexof ("O", 6));//o position first appearing after position 6, no return-1    //s.lastindexof ("x") x the last occurrence of the position, does not exist then returns-1Console.log (S.lastindexof ("O"));// AConsole.log (S.lastindexof ("z"));//-1Console.log (S.split (","));//Convert a string to an array based on ","Console.log (S.replace ("O", "O"));//Hellow,pomelott Replace the first "O" with "O"Console.log (S.touppercase ());//convert full text to uppercase    varStr1= "Hellow,"; varStr2= "World";  Console.log (Str1.concat (str2)); //Hellow,world String Connection    //The Search () method is used to retrieve the substring specified in a string, or to retrieve a substring that matches a regular expression. Console.log (S.search (/pomelo/));//7 exists then returns the first word Poute, does not exist then returns-1    //The match () method can be retrieved within a string based on a regular expression, or, if present, returns the retrieved object, otherwise nullConsole.log (S.match (/pomelo/));//["Pomelo", Index:7, Input: "Hellow,pomelott"]Console.log (typeofS.match (/pomelo/));//ObjectConsole.log (S.match ("Pop"));//NULL

A detailed description of string encoding and string methods in JavaScript