checkPerfectSquare()

Step 1: Understanding our goal

The goal of this function is to check whether a given number is a perfect square or not. A perfect square is a number that can be expressed as the product of an integer with itself. For example, the numbers 1, 4, 9 and 16 are perfect squares because they can be expressed as 11, 22, 33 and 44 respectively.

function checkPerfectSquare(number) {
  // Our goal is to implement the logic here
}

Step 2: Initial check for the input number

Before we can proceed, we should perform a basic check on the input number to ensure it is a positive integer.

In JavaScript, we can use the built-in Number.isInteger function to check if the number is an integer, and then additionally verify that the number is positive.

function checkPerfectSquare(number) {
  if (!Number.isInteger(number) || number < 1) {
    return false;
  }
}

Step 3: Calculating the square root

In the next step, we calculate the square root of the number. This is done using the Math.sqrt function in JavaScript.

The Math.sqrt function returns a floating point number which is actually the square root of the input number.

function checkPerfectSquare(number) {
  if (!Number.isInteger(number) || number < 1) {
    return false;
  }

  var sqrt = Math.sqrt(number);
}

Step 4: Checking if the square root is an integer

Now, let's say our number is a perfect square. Then in theory, the square root of such a number should be a whole number or an integer.

So, we check if the square root we calculated above is an integer or not.

Again, we can use JavaScript's Number.isInteger function for this.

function checkPerfectSquare(number) {
  if (!Number.isInteger(number) || number < 1) {
    return false;
  }

  var sqrt = Math.sqrt(number);
  return Number.isInteger(sqrt);
}

Conclusion

Our function checkPerfectSquare is complete. We have ensured that our function accepts only a positive integer as input, then calculates its square root and checks if this square root is an integer or not.

Here is the complete code:

function checkPerfectSquare(number) {
  // Step 1: Initial input check
  if (!Number.isInteger(number) || number < 1) {
    return false;
  }

  // Step 2: Calculating the square root
  var sqrt = Math.sqrt(number);

  // Step 3: Checking if square root is an integer
  return Number.isInteger(sqrt);
}

In this way, we have achieved our goal to write a function in JavaScript which checks if a given number is a perfect square.