addTwoNumbers()

Step 1: Define the Function

In JavaScript, we start by defining a function using the function keyword. This informs the JavaScript interpreter that we are about to define a function. We then give it a name, in this case addTwoNumbers as we want it to add two numbers together. The parentheses () that follow are for function arguments, in this case two numbers. We will call them number1 and number2. We also add the opening and closing curly braces {} that will contain our function's code.

function addTwoNumbers(number1, number2) {

}

Step 2: Implement the Addition

Inside our function, we want to perform the operation of adding number1 and number2. We will use the + operator to add the two numbers.

function addTwoNumbers(number1, number2) {
    var sum = number1 + number2;
}

Step 3: Return the Result

Our function now adds two numbers, but we want it to give us back the result, i.e., return the result. For this, we use the return keyword, followed by the result we want to return.

function addTwoNumbers(number1, number2) {
    var sum = number1 + number2;
    return sum;
}

Step 4: Testing the Function

Now that our function is complete, we want to test it. We can do so by calling it with some numbers and then logging the returned result to the console with console.log.

function addTwoNumbers(number1, number2) {
    var sum = number1 + number2;
    return sum;
}

console.log(addTwoNumbers(2, 3)); // Outputs: 5

Step 5: Refactor the Function

Our function works great, but it's a little bit longer than it needs to be. In JavaScript, you can return the result directly without needing to store it in a variable first.

function addTwoNumbers(number1, number2) {
    return number1 + number2;
}

console.log(addTwoNumbers(2, 3)); // Outputs: 5

Conclusion

In conclusion, we have written a JavaScript function addTwoNumbers that takes two arguments, adds them together, and returns the result. We have also demonstrated how to test this function and how it can be simplified by returning the result directly. This function will work for any two numbers you give it, making it a versatile tool in your JavaScript toolbox.