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Node.js Unicode Transcoding
Unicode encoding and decoding in Node.js is becoming more and more common. Its method of finding Unicode sequences is easy compared to many common programming languages. JavaScript naturally supports Unicode strings due to its built-in UTF-16 encoding mechanism. In this article, we will cover how to use Unicode encoding and decoding in Node.js.
Introduction to Unicode
Unicode is a character encoding designed to cover all character sets and assign them unique numeric code points. This means that Unicode can be used to represent almost all characters in any language, whether they are common or rare characters. It also supports Emoji and various symbols. Unicode uses 16-bit or 32-bit code units to represent all characters as numbers, called code points.
Using Unicode in JavaScript
JavaScript has built-in support for Unicode. In JavaScript, the UTF-16 encoding mechanism is used to store strings, and the u xxxx and u{xxxxx} syntax is allowed to represent Unicode code points (where x is a hexadecimal number). For example, here are examples of Unicode code points representing the Chinese character "中": u4e2d and u{4e2d}.
const str1 = "u4e2d";
const str2 = "u{4e2d}";
console.log(str1); // In
console.log(str2 ); // Medium
Using Unicode in Node.js
In Node.js, you can also use the Buffer object to handle Unicode encoding and decoding. Buffer can be thought of as an array of unsigned integers, with each element having a value between 0 and 255, but the toString method can be used to interpret the contents in a way that decodes the string as Unicode.
A common requirement is to convert a Unicode string to a byte array in UTF-8 encoding. This can be done by passing a string to the Buffer method:
const str = "Node.js is cool";
const buff = Buffer.from(str, "utf-8");
console.log(buff); //
Similarly, you can use the Buffer object to convert UTF-8 Converts the encoded byte array to the corresponding Unicode string. This can be done by using the toString method and passing the encoding as "utf-8":
const buff = Buffer.from([0x4e, 0x6f, 0x64, 0x65, 0x2e, 0x6a, 0x73, 0x20, 0x69, 0x73, 0x20, 0x63, 0x6f, 0x6f, 0x6c]);
const str = buff.toString("utf-8");
console.log(str); // Node. js is cool
It’s also easy to use UTF-16 encoding in Node.js. You can use the buffer method directly on the string and specify the encoding type as "utf-16le" or "ucs2":
const str = "Chinese";
const buff = Buffer.from(str , "ucs2");
console.log(buff); //
Convert UTF-16 encoded byte array to Unicode characters String:
const buff = Buffer.from([0xe4, 0xb8, 0xad, 0xe6, 0x96, 0x87]);
const str = buff.toString("ucs2");
console.log(str); // Chinese
Note that when using "ucs2" encoding, each Unicode code point is represented by 16-bit code units. If the Unicode code point is greater than 0xFFFF, another encoding must be used, such as UTF-16BE or UTF-16LE.
Conclusion
Node.js has built-in support for Unicode, making dealing with Unicode encoding and decoding simple and straightforward. You can use the built-in Unicode support in JavaScript, or you can use the Buffer object in Node.js for conversion. No matter which method you use, working with Unicode sequences is quick and easy.
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