05-Basic-operators.md

Basic Operators

Introduction

Operators in JavaScript are symbols or keywords used to perform operations on values or variables. In this section, we will cover some of the basic operators in JavaScript.

Arithmetic Operators

Arithmetic operators are used to perform arithmetic operations on numbers (literals or variables). The following table lists the arithmetic operators in JavaScript:

• + Addition - adds two numbers together
• - Subtraction - subtracts one number from another
• * Multiplication - multiplies two numbers together
• / Division - divides one number by another
• % Modulus - gives the remainder of one number divided by another

let a = 5;
let b = 2;
let c = a + b; // --> c now contains the value 7
let d = a - b; // --> c now contains the value 3
let e = a * b; // --> c now contains the value 10
let f = a / b; // --> c now contains the value 2.5
let g = a % b; // --> c now contains the value 1

Assignment Operators

Assignment operators are used to assign values to variables. They're like a shortcut for writing variable = variable + value. Here are some examples of assignment operators in JavaScript:

• = Assigns the value on the right to the variable on the left.
• += Adds the value on the right to the variable on the left, and assigns the result to the variable on the left.
• -= Subtracts the value on the right from the variable on the left, and assigns the result to the variable on the left.
• *= Multiplies the variable on the left by the value on the right, and assigns the result to the variable on the left.
• /= Divides the variable on the left by the value on the right, and assigns the result to the variable on the left.
• %= Calculates the modulo of the variable on the left and the value on the right, and assigns the result to the variable on the left.

let a = 5;
let b = a; // --> b now contains the value 5
a += 2; // --> a now contains the value 7
a -= 2; // --> a now contains the value 5
a *= 2; // --> a now contains the value 10
a /= 2; // --> a now contains the value 5
a %= 2; // --> a now contains the value 1

Comparison Operators

Comparison operators are like a referee in a wrestling match. They compare two values and declare a winner (or loser). Here are some examples of comparison operators in JavaScript:

• == Equal to - compares two values to see if they're equal, but they don't care about the data type.
• === Strict equal to - compares two values to see if they're equal, but they also check the data type.
• != Not equal to - compares two values to see if they're not equal, they don't care about the data type.
• !== Strict not equal to - compares two values to see if they're not equal, and also checks the data type.
• > Greater than
• < Less than
• >= Greater than or equal to
• <= Less than or equal to

let a = 5;
let b = "5";
let c = 2;
console.log(a == b); //  --> true - because they look the same
console.log(a === b); //  --> false - because they're not the same type
console.log(a != b); //  --> false - because string will converted into number and here both are same
console.log(a !== b); //  --> true - because they're not the same type
console.log(a > c); //  --> true - because 5 is greater than 2
console.log(a < c); //  --> false - because 5 is not less than 2
console.log(a >= c); //  --> true - because 5 is greater than or equal to 2
console.log(a <= c); //  --> false - because 5 is not less than or equal to 2

Logical Operators

• && Logical AND - checks if both conditions are true, and returns true only if both are true.

  let a = 5;
  let b = 10;
  let c = 15;
  console.log(a < b && b < c); //  --> true - because both conditions are true
  console.log(a < b && b > c); //  --> false - because one of the conditions is false

• || Logical OR - checks if at least one condition is true, and returns true if at least one is true.

  let a = 5;
  let b = 10;
  let c = 15;
  console.log(a < b || b > c); //  --> true - because at least one condition is true
  console.log(a > b || b > c); //  --> false - because both conditions are false

• ! Logical NOT - flips the value of a condition. If it's true, it returns false. If it's false, it returns true.

  let a = 5;
  let b = 10;
  let c = 15;
  console.log(!(a < b)); //  --> false - because a < b is true
  console.log(!(a > b)); //  --> true - because a > b is false