Decoding Arithmetic and Logical Operations in JavaScript

Welcome! Today, we will dive into the universe of JavaScript arithmetic and logical operations. Just like in math, arithmetic operations help us conduct simple calculations. Logical operations, on the other hand, allow us to evaluate conditions and make decisions. They're like controllers in a video game, deciding your character's next move based on current conditions.

So, if you were in a candy store with only $10 to spend and each candy cost $2, what would you do? You'd likely perform a division operation to find out how many candies you could buy. But what if you wanted to buy ice cream ($4) and chips ($3) too with your $10? That's where logical operations come to the fore, helping you evaluate the right decision. Let's dive in!

Arithmetic operations are pretty straightforward in JavaScript, just as they are in math. We use + for addition, - for subtraction, * for multiplication, / for division, % for getting the remainder of the division, and finally, ** for power operator.

// These are just like your typical calculator operations!

// Addition
let sum = 10 + 5; // Result: 15

// Subtraction
let difference = 10 - 5; // Result: 5

// Multiplication
let product = 10 * 5; // Result: 50

// Division
let quotient = 10 / 4; // Result: 2.5

// Remainder
let remainder = 14 % 4; // Result: 2 (14 = 4 * 3 + 2)

// Power
let powerResult = 10**3; // Result: 1000

As you can see above, the operators are placed between the numbers to conduct the calculations.

You might wonder - what about integer division? If I have $10 and I would like to know how many $3 candies I can buy for it, how do I find out the answer? Well, all numbers in JavaScript are floating point, but there is a way to find the integer part of the number:

const money = 10;
const candyPrice = 3;

const maxCandiesToBuy = Math.floor(money / candyPrice); // Prints: 3

So, in fact, we just apply Math.floor to retrieve the integer part (3) from the number 3.33333, rounding the number.

While arithmetic operations revolve around numeric calculations, logical operations deal with conditions. They return a boolean value: true or false. JavaScript uses AND (&&), OR (||), and NOT (!) for logical operations.

// Let's see how we can apply them:

console.log(true && true);      // 'true' AND 'true' = true 
console.log(true && false);     // 'true' AND 'false' = false
console.log(true || false);     // 'true' OR 'false' = true
console.log(false || false);    // 'false' OR 'false' = false
console.log(!true);             // NOT 'true' = false
console.log(!false);            // NOT 'false' = true

Here, we used the actual boolean values — true and false — to illustrate the basic workings of logical operators. In real life, however, these true and false will likely be some expressions, e.g., (a > 3) && (a < 5).