JavaScript string manipulation

CharAt (n)//returns the character of the specified position (n)　

　　　　var str= "ABCDEFGE";
Console.log (Str.charat (3)); Output d

IndexOf (s,n)//Returns the position of the s first word backward from the position of n

　　　　var str= "ABCDEFGE";

Console.log (Str.indexof ("E", 0)); Output 4
Console.log (Str.indexof ("E", 4)); Output 4
Console.log (Str.indexof ("E", 5)); Output 7

LastIndexOf (s,n)//Find s from N position forward

　　 　　var str= "ABCDEFGE";

Console.log (Str.lastindexof ("E", 7)); Output 7

toLowerCase ()//convert string to lowercase　

var strr= "ABC";
Console.log (Strr.tolowercase ()); Output ABC

toUpperCase ()//convert string to uppercase　　

var ast= "abc";
Console.log (Ast.touppercase ()); Output ABC

Slice (A, B)//extract and return the characters between a

　　　　　var str= "ABCDEFGE";

Console.log (Str.slice (2,3)); Output C

Split ("", N)//conditionally intercepts the character and converts it to a string (preceded by a condition, followed by a few characters conversion)

Replace (Regular)//convert the specified string to ...

JavaScript string manipulation