what is operators?
An operator in JavaScript is a special symbol or keyword used to perform operations on values and variables. The values that the operator acts upon are called operands.
- For example, in the expression let sum = 10 + 5;, the + symbol is the operator, while 10 and 5 are the operands.
Classification by Number of Operands
JavaScript operators are structurally divided into three main categories based on how many values they manipulate:
- Unary Operators: Work on a single operand (e.g., ++x or typeof x). Ex:
// Case 1: Postfix
let x = 12;
let y = x++;
console.log(x);
console.log(y);
// Case 2: Preifix
x = 10;
y = ++x;
console.log(x);
console.log(y);
- Binary Operators: Work on two operands (e.g., x + y or x == y). Ex:
10 + 20
// 30
20 - 5
// 15
30 / 6
// 5
Ternary Operator: Works on three operands. JavaScript has exactly one, the conditional operator (condition ? value1 : value2).
Ex:
const age = 18;
const status = age >= 18 ? "Adult" : "Minor";
console.log(status);
Operators types:
1. Arithmetic Operators
Used for mathematical calculations.
console.log(10 + 5); // 15
console.log(10 % 3); // 1
2. Assignment Operators
Used to assign values to variables.
let x = 10;
x += 5; //x=x+5
console.log(x); // 15
3. Comparison Operators
Used to compare values. They return true or false.
console.log(5 == "5"); // true
console.log(5 === "5"); // false
console.log(10 > 5); // true
4.logical operators
Logical operators in JavaScript are symbols used to combine or modify expressions to determine the logic between values and control program flow.
- While they are typically used with Boolean (true/false) values in conditional statements like if blocks, they can actually be applied to values of any data type.
1. Logical AND (&&)
Returns true only when all conditions are true.
The && operator stops at the first falsy value it encounters and returns it. If all values are truthy, it returns the last value.
Syntax
condition1 && condition2
Example:
let age = 20;
console.log(age > 18 && age < 30);
Output:
true
2. Logical OR (||)
Returns true if at least one condition is true.
The || operator stops at the first truthy value it encounters and returns it. If all values are falsy, it returns the last value.
Syntax:
condition1 || condition2
Example
let age = 15;
console.log(age < 18 || age > 60);
Output
true
3. Logical NOT (!)
Reverses the result.
true becomes false.
false becomes true.
Unlike && and ||, the ! operator always returns a strict boolean (true or false). It converts the operand to its boolean equivalent and then flips it.
Example
let isLoggedIn = true;
console.log(!isLoggedIn);
Output:
false
5. Increment and Decrement Operators
++ operator is used to increase the value by 1.
-- operator is used to decrease the value by 1.
let n = 5;
n++;
console.log(n); // 6
n--;
console.log(n); // 5
Pre and Post Increment
In JavaScript, the main difference between pre-increment and post-increment is the order in which the value is changed and returned. Both operations add 1 to the target variable, but they behave differently when used inside expressions, assignments, or functions.
Pre-Increment ++x Increments first, then returns.New value (after adding 1).
Post-Increment x++ Returns first, then increments.Old value (before adding 1).
same rule is applicable for decrement operator.
Example
let a = 5;
console.log(++a); // 6 (increment first)
let b = 5;
console.log(b++); // 5 (use first, then increment)
console.log(b); // 6
Remember
&& → All conditions must be true.
|| → At least one condition must be true.
! → Opposite of the condition.
References
https://www.freecodecamp.org/news/unary-binary-ternary-operators-javascript/
https://www.geeksforgeeks.org/javascript/javascript-operators/
Top comments (0)