JavaScript Convert Character to ASCII and Vice Versa

A quick guide to convert a character into ASCII code in javascript and vice versa.

1. Overview

In this tutorial, We'll learn how to convert a character into ASCII code in javascript and vice versa.

For character A, its ASCII code is 65

B = 66

a = 97

b = 98

0 = 48

For each character, there will be a unique ASCII code.

There are two ways to convert character to ASCII code in javascript using the below methods.

String.charCodeAt()

String.codePointAt()

To convert from Code Point ASCII code to character in javascript, use the below methods.

String.fromCharCode()

String.fromCodePoint()

2. JavaScript Character to ASCII Using String.charCodeAt() Function

charCodeAt() method takes the index of the character and returns UTF-16 code for the given index.

The first 128 Unicode points from 0 to 127 are used to match the ASCII character set.

Look at the below program.

var chracter = 'B';
var index = 0;
 
var asciiCode = chracter.charCodeAt(index);
console.log(asciiCode);

Output:

66

ASCII code for character B is 66. The same has been produced in the output console.

3. JavaScript Character to ASCII Using String. codePointAt() Function

When the String characters are having special characters such as codepoints then the charCodeAt() method does not work. In this case, you need to use the codePointAt() method.

codePointAt() method returns the integer value in between 0 and 65535.

Look at the below example script using codePointAt() function.

const sentence = 'hello welcome to the javascript char to ascii post';

const index = 7;

console.log(`The character code ${sentence.charCodeAt(index)} is equal to ${sentence.charAt(index)}`);

console.log('ABC'.charCodeAt(0));

Output:

"The character code 101 is equal to e"
65

4. JavaScript ASCII to Character Using String fromCharCode()

If you want to get the character from the ASCII codes, use the String.fromCharCode() method from the String object.

console.log(String.fromCharCode(65, 66)); 
console.log(String.fromCharCode(67, 68)); 
console.log(String.fromCharCode(69, 70)); 

Any no of arguments can be passed to fromCharCode() method and all characters are returned as String object by concatenating all characters of the given ASCII codes.

Output:

Look at the output how the fromCharCode() method has generated the output.

AB
CD
EF

5. JavaScript codepoints to a character using String.fromCodePoint()

String.fromCodePoint() is used to get the string from the given set of code points sequence.

This method also takes any no of arguments. Look at the below example with different arguments.

console.log(String.fromCodePoint(9731));
console.log(String.fromCodePoint(9731, 9733));
console.log(String.fromCodePoint(9735, 9737));
console.log(String.fromCodePoint(9731, 9733, 9842));
console.log(String.fromCodePoint(9731, 9733, 9842, 0x2F804));

Output:

"☃"
"☃★"
"☇☉"
"☃★♲"
"☃★♲你"

6. Conclusion

In this article, we've seen how to convert the character to ascii code in java script and vice versa with examples.

String API