Here are 2 examples of my code. The first one is:
console.log([4] + 10); //"410"
As far as I know, addition operator can work only with numbers and strings. So, firstly, [4] should be transformed into the number or string. When trying to convert an operand to a primitive data type, either valueOf() or toString() runs. By default, valueOf() returns an array, so this method is ignored. toString() is invoked. It converts the complex data type to a string. That's completely understandable for me, but...
What's going on in the second example?
console.log(10 - [4]); //6
I don't get how valueOf() can transform array into the number if this method by default returns an array. What does occur here?
It goes this way:
10 - [4]
10 - '4' // array to string
10 - 4 // implicit casting of all operands to number with minus operator
6 // result