charCodeAt JavaScript - String Method
This tutorial will explain to you to get the Unicode value of a character from a string and how to use the charCodeAt() method.
The Unicode is a number (or code) given to each character by the international standard from 0 to 65,535. For example, the character 'A' has a Unicode value of 65.
So how will you get a character code or Unicode value of a character from a string?
charCodeAt() method.

charCodeAt Method In JavaScript
The charCodeAt() method is used to get the Unicode value of any character from a string.
The method is applied on any string with the index value of the character and it returns an integer between 0 to 65,535.
Syntax
The syntax of charCodeAt() method is following:
string.charCodeAt(index)
You can use a string variable or direct any string to use the method. Let's see an example:
Example: Using direct string
console.log("ABC".charCodeAt(0));
console.log("ABC".charCodeAt(1));
console.log("ABC".charCodeAt(2));
Example: Using string variable
const quote = "Learning to code is learning to create and innovate";
console.log(quote.charCodeAt(0)); // first charater
console.log(quote.charCodeAt(quote.length - 1));// last charater
Index value in charCodeAt method
The index value passed in the string must lie between 0 and string.length - 1, if the index value is beyond this limit then it returns NaN
.
const quote = "Learning to code is learning to create and innovate";
console.log(quote.charCodeAt(-1)); // return NaN
console.log(quote.charCodeAt(100));// return NaN
The default value of the index is 0, which means if the index value is not provided or the given index is not a valid number the 0 is used as an index.
const quote = "Learning to code is learning to create and innovate.";
console.log(quote.charCodeAt()); // index not given (default index used = 0)
console.log(quote.charCodeAt("X")); // can't be converted to integer
Getting All Character Code Of String
To get all character code of a string simply loop through all the characters of the string and use the charCodeAt() method.
const alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
for (let i = 0; i < alphabets.length; i++) {
console.log(alphabets.charCodeAt(i));
}
Displaying character code at different index in String
Here is an example that displays characters code of string at a different position.
const quote = "Learning to code is learning to create and innovate.";
console.log("character code at index 0 is '" + quote.charCodeAt(0) + "'.");
console.log("character code at index 1 is '" + quote.charCodeAt(1) + "'.");
console.log("character code at index 2 is '" + quote.charCodeAt(2) + "'.");
console.log("character code at index 10 is '" + quote.charCodeAt(10) + "'.");
console.log("character code at index 20 is '" + quote.charCodeAt(20) + "'.");
console.log("character code at index 100 is '" + quote.charCodeAt(100) + "'.");
Points to remember:
- To get the character code at some index position in a string use charCodeAt() method.
- The returned character code value lies between 0 and 65,535.