(+)

console.log(2 + 2);
// : 4

console.log(2 + true);
// : 3

console.log("hello " + "everyone");
// : "hello everyone"

console.log(2001 + ": A Space Odyssey");
// : "2001: A Space Odyssey"

x + y

const t = Temporal.Now.instant();
"" + t; // TypeError 
`${t}`; // '2022-07-31T04:48:56.113918308Z'
"".concat(t); // '2022-07-31T04:48:56.113918308Z'

1 + 2; // 3

true + 1; // 2
false + false; // 0

1n + 2n; // 3n

1n + 2; // TypeError: Cannot mix BigInt and other types, use explicit conversions
2 + 1n; // TypeError: Cannot mix BigInt and other types, use explicit conversions

"1" + 2n; // "12"

1n + BigInt(2); // 3n
Number(1n) + 2; // 3

"foo" + "bar"; // "foobar"
5 + "foo"; // "5foo"
"foo" + false; // "foofalse"
"2" + 2; // "22"