DivideTwoNumbers()

Step 1: Defining the function

First of all, we need to define a function in Swift that will take two parameters: The dividend and the divisor. We'll name this function divideTwoNumbers.

func divideTwoNumbers(dividend: Double, divisor: Double) {

}

Step 2: Handle division by zero

Before proceeding with the division, we need to check if the divisor is zero to avoid the runtime error due to division by zero. If the divisor is zero, the function will return nil.

func divideTwoNumbers(dividend: Double, divisor: Double) {
    if divisor == 0 {
        return nil
    }
}

Step 3: Perform the division

Once we have ensured that the divisor is not zero, we can go ahead and perform the division using the / operator.

func divideTwoNumbers(dividend: Double, divisor: Double) -> Double? {
    if divisor == 0 {
        return nil
    }

    let result = dividend / divisor
    return result
}

Step 4: Calling the function

The function can be called with the values for the dividend and divisor arguments passed accordingly.

let result = divideTwoNumbers(dividend: 10, divisor: 2)
print(result)  // Prints Optional(5.0)

Conclusion

By following the steps, we have written a function that can perform division operation on two numbers while correctly handling the edge-case of division by zero. The complete code is as follows:

func divideTwoNumbers(dividend: Double, divisor: Double) -> Double? {
    if divisor == 0 {
        return nil
    }

    let result = dividend / divisor
    return result
}

let result = divideTwoNumbers(dividend: 10, divisor: 2)
print(result)  // Prints Optional(5.0)