Get Programming with JavaScript - Listing 6.04

Get Programming with JavaScript - Listing 6.04

Listing 6.04 - Returning the sum of two numbers

var add;

add = function (number1, number2) {
    var total = number1 + number2;

    return total;
};

var sum = add(50, 23);

console.log(sum);

Further Adventures

Listing 6.04 - Returning the sum of two numbers - Task 1

Find and display the sum of a different pair of numbers.

var add;

add = function (number1, number2) {
    var total = number1 + number2;

    return total;
};

var sum = add(500, -123);   // find the sum

console.log(sum);   // display the sum

Listing 6.04 - Returning the sum of two numbers - Task 2

Change the call to console.log so that the display on the console reads: 'The sum of 50 and 23 is 73' using the add function to generate the answer.

var add;

add = function (number1, number2) {
    var total = number1 + number2;

    return total;
};

var sum = add(50, 23);

// Update the message logged to the console
console.log("The sum of 50 and 23 is " + sum);

Listing 6.04 - Returning the sum of two numbers - Task 3

Can you use the add function as it is to add more than two numbers?

var add;

add = function (number1, number2) {
    var total = number1 + number2;
    return total;
};

// add three numbers
var sum = add(18, add(50, 23));

console.log("The sum of 18, 50 and 23 is " + sum);

Remember the return value replaces the function call, so add(18, add(50, 23)) becomes add(18, 73) which becomes 91.

Listing 6.04 - Returning the sum of two numbers - Task 4

Create a function to return the sum of three numbers given as arguments.

var add;
var add3;   // declare a variable

add = function (number1, number2) {
    var total = number1 + number2;
    return total;
};

// define a function and
// assign it to your variable
add3 = function (number1, number2, number3) {
    return add(number1, add(number2, number3));
};

var sum = add3(18, 50, 23);

console.log("The sum of 18, 50 and 23 is " + sum);

Of course it would be easier just to add the numbers directly.

var add3;

add3 = function (number1, number2, number3) {
    return number1 + number2 + number3;
};

var sum = add3(18, 50, 23);

console.log("The sum of 18, 50 and 23 is " + sum);