LESSON 17 OF 414 · CALCULATIONS WITH NUMBERS

Arithmetic Operators in TypeScript

Lesson

TL ; DR:

We can tell computers to perform calculations for us using +, -, *, /:

console.log(2 + 6); // Prints 8
console.log(10 - 7); // Prints 3
console.log(3 * 3); // Prints 9
console.log(6 / 2); // Prints 3

We can also use variables. In these examples, TypeScript will replace variable num with its value 6 to do the calculations:

let num = 6;
console.log(num + 5); // Prints 11
console.log(10 - num); // Prints 4
console.log(3 * num); // Prints 18
console.log(num / 2); // Prints 3

Full lesson:

Computers absolutely excel at performing calculations. The "compute" in their name comes from their historical association with providing answers to mathematical questions.

These calculations can be performed either directly with numbers or with variables that are assigned numeric values.

Arithmetic operators

Arithmetic operators are used with numeric values to perform common mathematical operations:

Operator	Name	Examples
+	Addition	3 + 5, x + 5, 3 + y, x + y
-	Subtraction	8 - 3, 8 - y, x - 3, x - y
*	Multiplication	3 * 5, 3 * y, x * 5, x * y
/	Division	8 / 4, 8 / y, x / 8, x / y
%	Modulus	8 % 4, 8 % y, x % 4, x % y
**	Exponentiation	3 2, 3 y, x 3, x y

Note that performing arithmetic on variables does not change the variable - you can only update a variable using the = sign.

Let's go through some examples together to better understand how each operator works:

Addition

// Declare 2 variables and initialize them:
let a = 2;
let b = 3;

console.log(a + b); // Output: 5

console.log(a + 10); // Output: 12

Subtraction

// Declare 2 variables and initialize them:
let a = 2;
let b = 3;

console.log(a - b); // Output: -1

console.log(10 - b); // Output: 7

Multiplication

// Declare 2 variables and initialize them:
let a = 2;
let b = 3;

console.log(a * 5); // Output: 10

console.log(-2 * a * b); // Output: -12

Division

// Declare 2 variables and initialize them:
let a = 2;
let b = 3;

console.log(b / a); // Output: 1.5

console.log(a / 10); // Output: 0.2

Exponentiation

The ** operator performs the exponential calculation (2**3 translates to 2 * 2 * 2):

// Declare 2 variables and initialize them:
let a = 2;
let b = 3;

console.log(2 ** 3); // Output: 8

console.log(b ** a); // Output: 9

We left the modulo operator (%) for the next lesson.

Assignment
Follow the Coding Tutorial and let's practice with arithmetic operators!

Hint
Look at the examples above if you get stuck.

STEP 1 OF 1

Guided

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