Javascript string indexof() method : the indexof() method is used to return the index value of specified string. it will give the index of string comes first from the start. we can also start ...

charAt(index) - Returns the character at a specified index/position. index is the string position of the desired character.

charCodeAt (index) - Returns the Unicode of the character at a specified index/position. concat (String1 [,String2, StringN]) - Returns two or more joined strings.