**What is Unicode?**
Unicode is a universal character encoding standard that aims to represent every character from all writing systems in the world. The core idea is simple: by assigning a unique number, called a "code point," to each character, computers can display text accurately without any issues like garbled or missing characters.
Each code point starts at 0 and is represented in hexadecimal format with the prefix "U+". For example, the null character is U+0000, which means all bits are zero. This system allows for a vast range of characters, including letters, symbols, and even emojis.
As of the latest version, Unicode 15.0 (released in 2023), it contains over 149,000 characters, with a large portion coming from East Asian scripts such as Chinese, Japanese, and Korean. For instance, the Chinese character for "good" (好) is represented by the code point U+597D.
Unicode is divided into 17 planes, each capable of holding 65,536 characters. The first plane, known as the Basic Multilingual Plane (BMP), includes the most commonly used characters and ranges from U+0000 to U+FFFF. The remaining planes, called the Supplementary Planes, accommodate less common or historical characters.
**What is JavaScript?**
JavaScript is a high-level, interpreted programming language primarily used for client-side web development. It is dynamic, weakly typed, and object-oriented, with support for functions and prototypes. JavaScript runs inside web browsers, enabling interactive elements on web pages, such as form validation, animations, and real-time updates.
Originally developed by Brendan Eich at Netscape in 1995, JavaScript was named to capitalize on the popularity of Java, although it is not related to the Java programming language. Its syntax is influenced by languages like C and Java but also shares similarities with Self and Scheme.
Over time, JavaScript evolved beyond the browser, becoming a versatile language used in server-side development (Node.js), mobile apps, and even desktop applications. To ensure consistency across platforms, JavaScript was standardized under ECMA International as ECMAScript. Today, it's one of the most widely used programming languages on the web.
**UTF-32 and UTF-8**
While Unicode defines the code points for characters, it doesn't specify how they should be stored in memory or transmitted over networks. That’s where encoding schemes like UTF-32 and UTF-8 come into play.
UTF-32 represents each code point using exactly four bytes, making it straightforward and efficient for direct access. However, this method is very space inefficient—especially for texts that mainly use ASCII characters. For example, the null character (U+0000) would be represented as 0x00000000, while the character “好†(U+597D) would be 0x0000597D. Due to its inefficiency, UTF-32 is rarely used in practice, especially in web technologies.
In contrast, UTF-8 is a variable-length encoding that uses 1 to 4 bytes per character. It is backward compatible with ASCII, meaning the first 128 characters (from U+0000 to U+007F) are represented using just one byte. This makes UTF-8 highly efficient for English text and widely adopted on the internet. It’s the default encoding for HTML, HTTP, and many other web protocols.
Because of its efficiency and flexibility, UTF-8 has become the most popular encoding method for web content and software worldwide.
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