JS Operators

Arithmetic Operator:

• Used for basic math operations.

  • Addition +
  • Subtraction -
  • Multiplication *
  • Division /
  • Modulus (remainder) %
  • Power **

let a = 20;
let b = 4;

// Addition (+)
let addition = a + b;
console.log("Addition (20 + 4):", addition);         // 24

// Subtraction (-)
let subtraction = a - b;
console.log("Subtraction (20 - 4):", subtraction);   // 16

// Multiplication (*)
let multiplication = a * b;
console.log("Multiplication (20 * 4):", multiplication); // 80

// Division (/)
let division = a / b;
console.log("Division (20 / 4):", division);         // 5

// Modulus / Remainder (%)
let modulus = a % b;
console.log("Modulus (20 % 4):", modulus);           // 0

// Exponentiation (**)
let exponentiation = a ** b;
console.log("Exponentiation (20 ** 4):", exponentiation); // 160000

Comparison Operators:

• Used to compare value. Returns true or false.

let a = 10;
let b = 20;
let c = "10";

// Equal to (==)  - compares value only (type conversion allowed)
console.log("Equal to (10 == 20):", a == b);         // false
console.log("Equal to (10 == '10'):", a == c);       // true  (type coercion)

// Strict Equal to (===)  - compares value and type
console.log("Strict Equal (10 === 10):", a === 10);  // true
console.log("Strict Equal (10 === '10'):", a === c); // false (different types)

// Not Equal to (!=)  - compares value only
console.log("Not Equal (10 != 20):", a != b);        // true
console.log("Not Equal (10 != '10'):", a != c);      // false (type coercion)

// Strict Not Equal to (!==)  - compares value and type
console.log("Strict Not Equal (10 !== 20):", a !== b);  // true
console.log("Strict Not Equal (10 !== '10'):", a !== c); // true (different types)

// Greater than (>)
console.log("Greater Than (10 > 20):", a > b);       // false
console.log("Greater Than (20 > 10):", b > a);       // true

// Less than (<)
console.log("Less Than (10 < 20):", a < b);          // true
console.log("Less Than (20 < 10):", b < a);          // false

// Greater than or Equal to (>=)
console.log("Greater or Equal (10 >= 10):", a >= 10); // true
console.log("Greater or Equal (10 >= 20):", a >= b);  // false

// Less than or Equal to (<=)
console.log("Less or Equal (10 <= 20):", a <= b);    // true
console.log("Less or Equal (20 <= 10):", b <= a);    // false

Assignment Operators :

let a = 50;
console.log("Assignment (a = 50):", a);              // 50

// Addition Assignment (+=) a = a + 10
a += 10;
console.log("Addition Assignment (a += 10):", a);    // 60

// Subtraction Assignment (-=) a = a - 5
a -= 5;
console.log("Subtraction Assignment (a -= 5):", a);  // 55

// Multiplication Assignment (*=) a = a * 2
a *= 2;
console.log("Multiplication Assignment (a *= 2):", a); // 110

// Division Assignment (/=) a = a / 5
a /= 5;
console.log("Division Assignment (a /= 5):", a);     // 22

// Modulus Assignment (%=) a = a % 8
a %= 8;
console.log("Modulus Assignment (a %= 8):", a);      // 6

// Exponentiation Assignment (**=) a = a ** 3
a **= 3;
console.log("Exponentiation Assignment (a **= 3):", a); // 216

Logical Operator:

// Logical AND (&&) - returns true only if both operands are true
console.log("AND (true && true):", a && a);          // true
console.log("AND (true && false):", a && b);         // false
console.log("AND (false && false):", b && b);        // false

// Logical OR (||) - returns true if at least one operand is true
console.log("OR (true || false):", a || b);          // true
console.log("OR (false || false):", b || b);         // false
console.log("OR (true || true):", a || a);           // true

// Logical NOT (!) - reverses the boolean value
console.log("NOT (!true):", !a);                     // false
console.log("NOT (!false):", !b);                    // true

Type of Operator :

• Returns the data type of a value as a string.

console.log("typeof 42:", typeof 42);                      // number
console.log("typeof 3.14:", typeof 3.14);                  // number
console.log("typeof 'hello':", typeof "hello");            // string
console.log("typeof true:", typeof true);                  // boolean
console.log("typeof undefined:", typeof undefined);        // undefined
console.log("typeof 9007199254740991n:", typeof 9007199254740991n); // bigint

Increment & Decrement :

//  Post-Increment (a++) 
// Uses the current value first, then increments by 1
let a = 5;
console.log("Initial a:", a);                        // 5
let postInc = a++;
console.log("postInc = a++ (value used):", postInc); // 5  (old value returned)
console.log("a after a++:", a);                      // 6  (incremented after)

// Pre-Increment (++a) 
// Increments first, then uses the new value
let b = 5;
console.log("Initial b:", b);                      // 5
let preInc = ++b;
console.log("preInc = ++b (value used):", preInc);   // 6  (incremented before returning)
console.log("b after ++b:", b);                      // 6

// Post-Decrement (a--) 
// Uses the current value first, then decrements by 1
let c = 10;
console.log("Initial c:", c);                      // 10
let postDec = c--;
console.log("postDec = c-- (value used):", postDec); // 10 (old value returned)
console.log("c after c--:", c);                      // 9  (decremented after)

//  Pre-Decrement (--a) 
// Decrements first, then uses the new value
let d = 10;
console.log("Initial d:", d);                      // 10
let preDec = --d;
console.log("preDec = --d (value used):", preDec);   // 9  (decremented before returning)
console.log("d after --d:", d);    //9