JavaScript · Senior · Question 45 of 75

What does the expression return?

const obj = {
  [Symbol.toPrimitive](hint) {
    return hint === "number" ? 42 : "obj";
  },
};
console.log(+obj, `${obj}`);

✓Correct answer: 42 obj
2NaN [object Object]
342 42

Explanation

When converting to a primitive, the engine calls Symbol.toPrimitive with the hint 'number', 'string' or 'default'. Without it, valueOf and toString are used. This is how, for example, date subtraction works: date2 - date1.

What does the expression return?

Explanation

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