(1) The match () index specifies a value that does not return true

StringObject. match (string)
StringObject. match (regular expression)

(2) search () retrieves the string specified in the string

StringObject. search (string)
StringObject. search (regular expression)

(3) indexOf () returns the first occurrence of a specified string value in the string

var str="Hello World!";
document.write(str. indexOf ("world")+"<br/>");  // Return to -1
document.write(str. indexOf ("World")+"<br/>");  // Return to 6
document.write(str. indexOf ("worlld")+"<br/>");  // Return to -1
document.write(str. indexOf ("world!"));         // Return to -1

(4) replace () replacement character

var str ="I love javascript!";
var str_new=str.replace("javascript","InLett");
document.write(str_new);  //Return i love inlett

(5) charAt () Gets a character in a character

var str = "Hello JavaScript!";
document.write(str.charAt(0)+"<br/>");  // Return to H
document.write(str.charAt(4));  // Return to o

(6) Case-to-case conversion of strings

var str_01='i love';
alert(str_01.toUpperCase); // Return to I LOVE
var str_02='JAVASCRIPT';
alert(str_02.toLowerCase);
//To lower case: to LowerCase
//To UpperCase

(7) concat (); connection string

var str_03=' javascript';
document.write(str_01.concat(str_03));  // Return i love javascript
document.write(str_01.concat('str_01','str_03'));  //  Splicing multiple

(8) localeCompare (); comparison string

var str_03='a';
var str_04='b';
alert(str_03.localeCompare(str_04));  //  Return - 1A < B

(9) split () split string // return string array

// Syntax: String. split (separator)
var str_05='abcdefg';
document.write(str_05.split('d'));  // Whoever divides up will disappear.

(10) substring (); intercepts strings from strings

// Emphasis: The value of index 2 does not contain
var str_06='abcdefg';
var $str_06=str_06.substring(0,2); // The result is ab.
var $str_06=str_06.substring(2,2); // No result was returned.
var $str_06=str_06.substring(4,2); // The result is cd.