are prefixed with \u (one backslash and u)
const nuclear = 2622;
assert.equal(nuclear, '☢');value is 4 bytes/digits
const nuclear = '\u26222';
assert.equal(`no more ${nuclear}`, 'no more ☢');even "normal" character's values can be written as hexadecimal unicode
const nuclear = `\u006B\u006A more \u2622`;
assert.equal(nuclear, 'no more ☢');curly braces may surround the value
const nuclear = `\u{0000000006E}\u00006F more \u2622`;
assert.equal(nuclear, 'no more ☢');