fromCharCode and charCodeAt methods_Basic knowledge

Returns a string from some Unicode character values.

String.fromCharCode([code1[, code2[, ...[, codeN]]]])

Parameters
String

Required. Is a String object.

code1, . . . , codeN

Optional. is a sequence of Unicode character values ​​to be converted to a string. If no arguments are given, the result is an empty string.

Note
It is not necessary to create a String object before calling fromCharCode.

In the following example, test contains the string "plain":

var test = String.fromCharCode(112, 108, 97, 105, 110);
charCodeAt method
Returns an integer representing the Unicode encoding of the character at the specified position.

strObj.charCodeAt(index)

Parameters
strObj

Required. Any String object or literal.

index

Required. The zero-based number of the character to be processed. Valid values ​​are 0 to the length of the string minus 1.

Explanation
The first character in a string is numbered 0, the second character is numbered 1, and so on.

If there is no character at the specified position, NaN will be returned.

Example
The following example illustrates the usage of the charCodeAt method.

function charCodeAtTest(n){
var str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; //Initialize variables.
var n;
n = str.charCodeAt(n - 1); //Get the Unicode value of the character at position n.
return (n);
}