JavaScript Program to Determine the Unicode Code Point at a Given Index

It is important to know what the Unicode code points are before moving on to the JavaScript implementation. A Unicode code point is a distinct integer value that represents each character in a string. A programmer may easily manipulate strings using JavaScript’s techniques for working with these code points.

Using the codePointAt() Method

JavaScript provides the codePointAt() method for strings, which returns the Unicode code point of the character at a specified index. The index refers to the position of the character in the string, starting from 0.

Syntax:

string.codePointAt(index);

Example: The below code implements the codePointAt() method to get the Unicode point at a given index.

Javascript

let str = "Hello, World!";

let result1 = str.codePointAt(0);
let result2 = str.codePointAt(7);

console.log(
    "Unicode point of character at index 0 in",
    str, "is:", result1);
console.log(
    "Unicode point of character at index 7 in",
    str, "is:", result2);

Output

Unicode point of character at index 0 in Hello, World! is: 72
Unicode point of character at index 7 in Hello, World! is: 87

Using the charCodeAt() Method

The charCodeAt() method returns the code unit at a given index, while codePointAt() clearly gets the single-character Unicode code point. Remember that JavaScript strings employ UTF-16 encoding, and that certain characters that are not part of the Basic Multilingual Plane (BMP) call for two code units, or surrogate pairs, which are represented by separate charCodeAt() values.

Example: The below code uses the charCodeAt() method to determine unicode point at a given index.

Javascript

const str = "𝌆GeeksforGeeks";
const codePoint1 = str.codePointAt(0);
const codeUnit1 = str.charCodeAt(0);
const codeUnit2 = str.charCodeAt(3);

console.log(codePoint1);
console.log(codeUnit1);
console.log(codeUnit2);

Output

119558
55348
101

Using the fromCodePoint() Method

The codePointAt() method is reversed by this technique. This function generates a string with the matching characters from an integer, or an array of integers, that represent Unicode code points.

Example: The below code implements the fromCodePoint() method to get unicode point t a given index.

Javascript

const codePoint = 128512;
const emojiString =
    String.fromCodePoint(codePoint);

console.log(emojiString);

Output

😀

Practical Applications

Determining Unicode code points empowers various tasks:

• Character Analysis: Analyze language distribution by counting code points within specific ranges.

• Text Encoding: Convert text between different encodings like UTF-8 and UTF-16 based on code point values.

• Font Development: Ensure fonts correctly display characters by mapping code points to glyphs.

• Emojis and Special Characters: Work with emojis and special characters effectively by using their code points.