Описание тега fromcharcode
String.fromCharCode() is a static method in JavaScript that returns a string based on the unicode number passed in. To use this tag, the question must be using JavaScript and one of the primary issues is regarding String.fromCharCode().
String.fromCharCode() accepts UTF-16 code units and converts them to the representative string.
String.fromCharCode(65) // returns A
The method can accept up to 65535 code units to return multiple characters.
String.fromCharCode(65, 66, 67) // returns ABC
If the method is called with no parameters, it outputs a zero-length string.
You can also pass parameters in hexadecimal notation.
String.fromCharCode(0x41) // returns A
If a number larger than 65535 (0xFFFF) is passed as a parameter it will be truncated. For example:
String.fromCharCode(65535)
65535 (1111111111111111) is the maximum and will output. However,
String.fromCharCode(65536)
65536 (10000000000000000) is over the maximum 16 bits and so will get truncated to 0000000000000000 which will then output a zero-length string.
References