calculateAreaRhombus()

Step 1: Understand the problem

The goal is to write a JavaScript function that calculates the area of a rhombus based on its diagonals. The formula for the area of a rhombus is: Area = 1/2 x (diagonal1 x diagonal2).

Step 2: Prepare the function structure

Let's start by preparing the structure of the function. In this step, the function calculateAreaRhombus takes two arguments, diagonal1 and diagonal2:

function calculateAreaRhombus(diagonal1, diagonal2) { 
  // Logic to calculate area goes here 
}

Step 3: Add error handling for invalid arguments

Before we compute the area, it's a good practice to validate the input parameters. We should ensure that diagonal1 and diagonal2 are both positive numbers:

function calculateAreaRhombus(diagonal1, diagonal2) { 
  if (diagonal1 <= 0 || diagonal2 <= 0) { 
    throw new Error('Diagonals must be positive numbers');
  }
  // Logic to calculate area goes here 
}

Step 4: Compute the area

After checking validity of the diagonals, we can safely calculate the area using the formula: 1/2 * (diagonal1 * diagonal2):

function calculateAreaRhombus(diagonal1, diagonal2) { 
  if (diagonal1 <= 0 || diagonal2 <= 0) { 
    throw new Error('Diagonals must be positive numbers');
  }
  const area = 0.5 * diagonal1 * diagonal2;
  // return the result 
}

Step 5: Return the result

Finally, return the area from the function so that it can be used:

function calculateAreaRhombus(diagonal1, diagonal2) { 
  if (diagonal1 <= 0 || diagonal2 <= 0) { 
    throw new Error('Diagonals must be positive numbers');
  }
  const area = 0.5 * diagonal1 * diagonal2;
  return area;
}

Conclusion

We have now created a function in JavaScript that takes the lengths of the two diagonals of a rhombus as arguments, validates these inputs, and calculates the area of the rhombus based on these diagonals.