Define an array of numbers in JavaScript: $5,10,$ and $7.$ You have to write two functions. The first function will add one $(+1)$ to each number in the array. While the second will subtract two $(-2)$ of each number in the array. Before doing any operation on the numbers, check if the number is less than $0.$ If it is$,$ do not subtract $-2.$

Suppose the span tag used to display the number in HTML code is like this:

Please note that you cannot use jQuery or any external library.

It is important to explain each line of code in detail.f