findSquareRoot()

Step 1: Understand the Problem

The first step in solving this problem is to understand what is being asked. We are asked to write a JavaScript function that is able to calculate and return the square root of a given number.

Step 2: Start Writing the Function

The next step would be to start writing the function. In JavaScript, we start defining a function with the function keyword, followed by the name of the function and any parameters it takes.

function findSquareRoot(number) {

}

Step 3: Incorporate the Math Object

Since we are asked to find the square root, we can make our task easier by using the JavaScript's built-in global Math object. Math object has a method sqrt() which returns the square root of a number.

This is our function so far:

function findSquareRoot(number) {
    return Math.sqrt(number);
}

Step 4: Add Error Checking

Although this function works perfectly fine, but it doesn't account for one thing: what if the user gives an input which is not a number? Or what if a negative number is passed?

To account for this, we'll add a condition that checks if the number is a positive number and is not a NaN. If this condition fails, we'll return a message instructing the user to input a valid number.

function findSquareRoot(number) {
    if(isNaN(number) || number < 0){
        return 'Please provide a valid number!';
    }
    return Math.sqrt(number);
}

Step 5: Testing the Function

Now that our function seems complete, we should now test it out with different edge-cases to ensure its working as expected.

If we run findSquareRoot(9), it should return 3 as 3 is the square root of 9.

If we run findSquareRoot(-1), it should return 'Please provide a valid number!' as square root of negative numbers is not a real number.

If we run findSquareRoot('Hello'), it should return 'Please provide a valid number!' as 'Hello' is not a valid number.

Conclusion

This illustrates the steps to write a function findSquareRoot in Javascript. The function takes a number as input and returns the square root of the number. It also accounts for cases where the input might not be a valid number.

Here is the final implementation of the function:

function findSquareRoot(number) {
    if(isNaN(number) || number < 0){
        return 'Please provide a valid number!';
    }
    return Math.sqrt(number);
}