Hint
Unary + is the fastest type-to-number conversion. Memorize: null→0, undefined→NaN, []→0, {}→NaN.
console.log(+true);
console.log(+false);
console.log(+null);
console.log(+undefined);
console.log(+'42');
console.log(+'');
console.log(+[]);
console.log(+{});1 0 0 NaN 42 0 0 NaN
Explanation: Unary + converts to number. true→1, false→0, null→0, undefined→NaN. "42"→42, ""→0. []→""→0. {}→"[object Object]"→NaN.
Key Insight: Unary + is the fastest type-to-number conversion. Memorize: null→0, undefined→NaN, []→0, {}→NaN.