calculateProductNumbersRange()

Step 1: Understand the Objective

To begin with, we must first understand the problem statement. We want to write a function called calculateProductNumbersRange. This function should take two numbers as inputs: the start and end of a range (both inclusive). The function will then calculate the product of all the numbers within this range.

For instance, if we call calculateProductNumbersRange(1, 4), the function should return the result of 1 * 2 * 3 * 4 which equals 24.

Step 2: Define the Function

First, we need to define our function. In JavaScript, this can be done using the function keyword. We know from our problem statement that the function should take two parameters - the start and end of the range, so we can include these as parameters in our function definition.

function calculateProductNumbersRange(start, end) {

}

Step 3: Create a Loop

Next, we need to set up a loop that will iterate over all the numbers in the provided range. For this, we will use a for loop, which in JavaScript takes the form for ([initialization]; [condition]; [final-expression]). Our loop will start from the start number and continue up to the end number.

function calculateProductNumbersRange(start, end) {
    for (let i = start; i <= end; i++) {

    }
}

Step 4: Calculate the Product

Within our for loop, we'll calculate the product of the numbers. Let's declare a variable product at the start of our function and set it to 1. Then, inside our loop, we'll multiply product by the current number i.

function calculateProductNumbersRange(start, end) {
    let product = 1;
    for (let i = start; i <= end; i++) {
        product *= i;
    }
}

Final Step: Return the Result

Finally, we need to return the product as the result from our function. We can achieve this by adding a return statement after our for loop.

function calculateProductNumbersRange(start, end) {
    let product = 1;
    for (let i = start; i <= end; i++) {
        product *= i;
    }
    return product;
}

Conclusion

So that's our function! This piece of code will take a start and end number as arguments and return the product of all numbers in the range. We've used a for loop to iterate over all the numbers, and a variable product to maintain the resulting product, which is returned as output.