How to get a random character from a range in JavaScript?

You can do this :

String.fromCharCode(0x30A0 + Math.random() * (0x30FF-0x30A0+1));

Note that 0x30FF-0x30A0 is 95, and if you want the last one you must add 1 (Math.random returns a result in [0,1[), which makes 96, not 60.

You can do this:

String.fromCharCode(Math.floor(Math.random() * 65535));

Because maximum hex is 65536.

Maximum hex: 16 ^ 4