Operators and Expressions in JavaScript

Key Concepts

• Arithmetic Operators
• Assignment Operators
• Comparison Operators
• Logical Operators
• String Operators
• Conditional (Ternary) Operator

Arithmetic Operators

Arithmetic operators are used to perform mathematical operations on numbers. These include addition (+), subtraction (-), multiplication (*), division (/), and modulus (%).

Example:

let a = 10;
let b = 5;
let sum = a + b; // 15
let difference = a - b; // 5
let product = a * b; // 50
let quotient = a / b; // 2
let remainder = a % b; // 0
    

Assignment Operators

Assignment operators are used to assign values to variables. The basic assignment operator is (=), but there are also compound assignment operators like +=, -=, *=, /=, and %=.

Example:

let x = 10;
x += 5; // x is now 15
x -= 3; // x is now 12
x *= 2; // x is now 24
x /= 4; // x is now 6
x %= 5; // x is now 1
    

Comparison Operators

Comparison operators are used to compare two values and return a Boolean result (true or false). These include == (equal to), === (equal value and type), != (not equal), !== (not equal value or type), > (greater than), < (less than), >= (greater than or equal to), and <= (less than or equal to).

Example:

let num1 = 10;
let num2 = 5;
let isEqual = num1 == num2; // false
let isIdentical = num1 === num2; // false
let isNotEqual = num1 != num2; // true
let isGreater = num1 > num2; // true
let isLessOrEqual = num1 <= num2; // false
    

Logical Operators

Logical operators are used to combine multiple conditions. These include && (logical AND), || (logical OR), and ! (logical NOT).

Example:

let isTrue = true;
let isFalse = false;
let andResult = isTrue && isFalse; // false
let orResult = isTrue || isFalse; // true
let notResult = !isTrue; // false
    

String Operators

String operators are used to concatenate strings. The + operator can be used to combine two or more strings.

Example:

let firstName = "John";
let lastName = "Doe";
let fullName = firstName + " " + lastName; // "John Doe"
    

Conditional (Ternary) Operator

The conditional operator is a shorthand way to write conditional statements. It takes three operands: a condition followed by a question mark (?), then an expression to execute if the condition is true, followed by a colon (:), and finally an expression to execute if the condition is false.

Example:

let age = 20;
let canVote = (age >= 18) ? "Yes" : "No"; // "Yes"
    

Conclusion

Understanding operators and expressions is fundamental to mastering JavaScript. By using arithmetic, assignment, comparison, logical, string, and conditional operators, you can perform a wide range of operations and make your code more dynamic and efficient.