JavaScript Conditional Statements

Conditional statements allow your code to make decisions and execute different blocks of code based on conditions. This is essential for creating dynamic and responsive applications.

Types of Conditional Statements

if: Executes a block of code if a specified condition is true.
else: Executes a block of code if the same condition is false.
else if: Tests a new condition if the first one is false.
switch: Provides multiple alternative blocks of code for execution (covered in another section)

The if Statement

The if statement executes a block of code if a specified condition evaluates to true.

Syntax

if (condition) {
 // Code to execute if the condition is true
}

Example

let hour = 15;
if (hour < 18) {
 console.log("Good day");
}
// Output: Good day

The else Statement

The else statement executes a block of code when the if condition is false.

Syntax

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

Example

let hour = 20;
if (hour < 18) {
 console.log("Good day");
} else {
 console.log("Good evening");
}
// Output: Good evening

The else if Statement

The else if statement allows you to check multiple conditions in sequence.

Syntax

if (condition1) {
 // Code to execute if condition1 is true
} else if (condition2) {
 // Code to execute if condition1 is false and condition2 is true
} else {
 // Code to execute if both conditions are false
}

Example

let time = 9;
if (time < 10) {
 console.log("Good morning");
} else if (time < 20) {
 console.log("Good day");
} else {
 console.log("Good evening");
}
// Output: Good morning

Example: Random Link Selection

This example demonstrates conditional logic using a random number to choose between two links.

let text;
if (Math.random() < 0.5) {
 text = "Visit JavaScript Guide";
} else {
 text = "Visit Wildlife Conservation";
}
console.log(text);

Possible Outputs:

Visit JavaScript Guide

OR

Visit Wildlife Conservation