How to get the Unicode code point for a character in Javascript?

Javascript strings have a method codePointAt which gives you the integer representing the Unicode point value. You need to use a base 16 (hexadecimal) representation of that number if you wish to format the integer into a four hexadecimal digits sequence (as in the response of Nikolay Spasov).

var hex = "▄".codePointAt(0).toString(16);
var result = "\\u" + "0000".substring(0, 4 - hex.length) + hex;

However it would probably be easier for you to check directly if you key code point integer match the expected code point

oEvent.key.codePointAt(0) === '▄'.codePointAt(0);

Note that "symbol equality" can actually be trickier: some symbols are defined by surrogate pairs (you can see it as the combination of two halves defined as four hexadecimal digits sequence).

For this reason I would recommend to use a specialized library.

you'll find more details in the very relevant article by Mathias Bynens

var hex = "▄".charCodeAt(0).toString(16);
var result = "\\u" + "0000".substring(0, 4 - hex.length) + hex;