如何将字符串转换为 unicode 字符？

Question

In Javascript '\\uXXXX' returns in a unicode character. But how can I get a unicode character when the XXXX part is a variable?

For example:

var input = '2122';
console.log('\\u' + input);             // returns a string: "\u2122"
console.log(new String('\\u' + input)); // returns a string: "\u2122"

The only way I can think of to make it work, is to use eval ; yet I hope there's a better solution:

var input = '2122';
var char = '\\u' + input;
console.log(eval("'" + char + "'"));    // returns a character: "™"

Answer 1

Use String.fromCharCode() like this: String.fromCharCode(parseInt(input,16)) . When you put a Unicode value in a string using \\u\u003c/code> , it is interpreted as a hexdecimal value, so you need to specify the base (16) when using parseInt .

Answer 2

String.fromCharCode("0x" + input)

or

String.fromCharCode(parseInt(input, 16)) as they are 16bit numbers (UTF-16)

Answer 3

JavaScript uses UCS-2 internally.

Thus, String.fromCharCode(codePoint) won't work for supplementary Unicode characters. If codePoint is 119558 ( 0x1D306 , for the '𝌆' character), for example.

If you want to create a string based on a non-BMP Unicode code point, you could use Punycode.js 's utility functions to convert between UCS-2 strings and UTF-16 code points:

// `String.fromCharCode` replacement that doesn’t make you enter the surrogate halves separately
punycode.ucs2.encode([0x1d306]); // '𝌆'
punycode.ucs2.encode([119558]); // '𝌆'
punycode.ucs2.encode([97, 98, 99]); // 'abc'

Answer 4

Since ES5 you can use

String.fromCodePoint(number)

to get unicode values bigger than 0xFFFF.

So, in every new browser, you can write it in this way:

var input = '2122';
console.log(String.fromCodePoint(input));

or if it is a hex number:

var input = '2122';
console.log(String.fromCodePoint(parseInt(input, 16)));

More info:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCodePoint

Answer 5

var hex = '2122';
var char = unescape('%u' + hex);

console.log(char);

will returns " ™ "