Working with text in JavaScript often involves dealing with Unicode characters. Unicode is a universal character encoding standard that assigns a unique number to every character, regardless of the platform, program, or language. This article provides a detailed guide on how to handle Unicode characters in JavaScript, including how to convert them and display them correctly.
In JavaScript, Unicode characters can be represented using escape sequences. An escape sequence is a combination of characters that represents a single character that cannot be directly typed or is reserved for other purposes.
\uXXXX, where XXXX is a four-digit hexadecimal number representing the Unicode code point.For example, the Unicode escape sequence for the less-than sign (<) is \u003c, and for the greater-than sign (>) it is \u003e. These escape sequences are often used in JSON responses or when dealing with special characters in strings.
JavaScript automatically interprets Unicode escape sequences within strings. This means you don't always need to perform a conversion.
let str = "Turn \u003cb\u003eleft\u003c/b\u003e";
console.log(str); // Output: Turn <b>left</b>
In this example, JavaScript automatically converts the Unicode escape sequences \u003c and \u003e to their corresponding HTML tags < and >, respectively.
JSON.parse()The JSON.parse() method can be used to parse a JSON string and automatically convert Unicode characters to their HTML counterparts.
let jsonString = JSON.stringify({ text: "Turn \u003cb\u003eleft\u003c/b\u003e" });
let parsedObject = JSON.parse(jsonString);
console.log(parsedObject.text); // Output: Turn <b>left</b>
This method is particularly useful when dealing with JSON responses from APIs where Unicode characters are encoded as escape sequences. You can learn more about JSON parsing in JavaScript on the Mozilla Developer Network.
normalize() Method (ES6/ES2015)ECMAScript 2015 (ES6) introduced the normalize() method on the String prototype, which can be used to normalize Unicode strings. While it doesn't directly convert Unicode escape sequences to HTML tags, it ensures that the string is in a standard Unicode format.
let directions = "Turn \u003cb\u003eleft\u003c/b\u003e onto \u003cb\u003eEnggårdsgade\u003c/b\u003e";
let normalizedDirections = directions.normalize();
console.log(normalizedDirections); // Output: Turn <b>left</b> onto <b>Enggårdsgade</b>
When displaying Unicode characters in HTML, the browser automatically interprets the Unicode escape sequences and renders the corresponding characters.
document.body.innerHTML = "Turn \u003cb\u003eleft\u003c/b\u003e"; // Displays: Turn <b>left</b>
This is because the browser understands the Unicode escape sequences and renders them as HTML tags.
<head> section of your HTML file:<meta charset="UTF-8">
< represents the less-than sign (<), and > represents the greater-than sign (>).Handling Unicode characters in JavaScript is often straightforward, as JavaScript automatically interprets Unicode escape sequences within strings. By understanding how Unicode escape sequences work and utilizing methods like JSON.parse() and normalize(), you can effectively manage and display Unicode characters in your JavaScript applications.
