convertOctalToBinary()

Step 1

The first step involves defining the conversion function. This function will be named octalToBinary and takes in an octal number as its parameter. Since we will be utilizing JavaScript's inbuilt function parseInt(), we must ensure that the input is a string. This is due to parseInt() taking a string as a parameter.

function octalToBinary(octal) {
  //check if input is a string
  if(typeof octal !== 'string') {
    octal = octal.toString();
  }
  //rest of implementation to follow
}

Step 2

In this step, we convert the octal to a decimal number using parseInt(). The function takes in two parameters: the string to convert and the base of the provided number. Since our string is an octal number, the base will be 8.

function octalToBinary(octal) {
  if(typeof octal !== 'string') {
    octal = octal.toString();
  }
  let decimal = parseInt(octal, 8);
  //rest of implementation to follow
}

Step 3

Next, we convert the decimal number to binary. JavaScript's toString() method comes in handy here. toString() takes a base as its parameter, and since we want to convert to binary, we pass in 2 as the base.

function octalToBinary(octal) {
  if(typeof octal !== 'string') {
    octal = octal.toString();
  }
  let decimal = parseInt(octal, 8);
  let binary = decimal.toString(2);
  //rest of implementation to follow
}

Step 4

At this point, we have successfully converted the octal number to binary. The final step in our function is to return this binary value.

function octalToBinary(octal) {
  if(typeof octal !== 'string') {
    octal = octal.toString();
  }
  let decimal = parseInt(octal, 8);
  let binary = decimal.toString(2);
  return binary;
}

Conclusion

With this, we have successfully walked through how one can convert an octal number to binary in JavaScript. This can be quite useful in many programming situations and reinforces our understanding of number systems. Keep in mind that understanding of how different number systems work will enhance your problem-solving skills. Remember always to validate your function with several test cases to ensure that it works as expected.

Here's the final version of our function:

function octalToBinary(octal) {
  if(typeof octal !== 'string') {
    octal = octal.toString();
  }
  let decimal = parseInt(octal, 8);
  let binary = decimal.toString(2);
  return binary;
}

With a test case to verify our function:

console.log(octalToBinary('123'));  // should return: '1010011'