Conditional Statements in JavaScript:

What are Conditional Statements in JavaScript?

• Conditional statements are used to make decisions in a program.

Conditional statements include:

1. if
2. if...else
3. if...else if...else
4. switch
5. ternary (? :)

1. if Statement:

• Executes code only if the condition is true

let age = 20;

if (age >= 18) {
  console.log("You are an adult");
}

2. else Statement:

• Use else to specify a code block to be executed if the same condition is false.

if (condition) {
  // code to execute if the condition is true
} else {
  // code to execute if the condition is false
}

3. else if Statement:

• Used to check multiple conditions

let marks = 75;

if (marks > 90) {
  console.log("Excellent");
} else if (marks > 60) {
  console.log("Good");
} else {
  console.log("Average");
}

4. switch Statement:

• Used to compare one value with multiple cases

let day = 2;

switch (day) {
  case 1:
    console.log("Monday");
    break;
  case 2:
    console.log("Tuesday");
    break;
  default:
    console.log("Invalid");
}

1. Ternary Operator:

• Short form of if-else

condition ? expression1 : expression2


If the value of age is < 18, 
set the value of text to "Minor", otherwise to "Adult":

let text = (age < 18) ? "Minor" : "Adult";

Important Concepts of javascript is: Truthy Falsy:

• In JavaScript, every value is treated as either true or false when used inside a condition.

This is known as truthy and falsy values

• Truthy → behaves like true
• Falsy → behaves like false

Falsy Values:
Falsy values are values that are considered false in a boolean context.

List of Falsy Values:

false
0
""
null
undefined
NaN

Example of Falsy:

let value = 0;

if (value) {
  console.log("Truthy");
} else {
  console.log("Falsy");
}

O/P: Falsy

Truthy Values

• All values except falsy values are truthy.

Why It is Important:

*Reduces code length (no need for multiple conditions)
*Reduces unnecessary comparisons
*Useful for checking if a value exists
*Widely used in real-time applications (forms, APIs, login)