What will be the output when calling multiply() four times in succession, where multiply is defined as: const multiply = (x = { ...value }) => { console.log((x.number *= 2)); };?

In the provided function definition, when you call multiply() for the first time, a new object is created using the spread syntax with the default value of x set to an object containing a property number. If the original value object is defined outside of this function and initialized with a property number set to 20, the output will be as follows for subsequent calls.

On the first call to multiply(), the value of x.number is initialized as 20, and then it gets multiplied by 2, resulting in 40. The function then logs this value. For the second call, the default parameter is used again, meaning that a new instance of x is created with a fresh copy of the value object. Hence, the value of number starts again from 20, resulting in a logged output of 40 again.

However, the important part of the code is the spread syntax. Every time you call multiply(), a new shallow copy of the value object is created, which starts with number at 20 again. For each subsequent call, the object reference is different because a new object is created with each invocation.

Therefore, when observing