JavaScript If Else

JavaScript If Else – Conditional Statements Explained

The if...else statement is used to perform different actions based on different conditions. It allows you to test if a condition is true or false and execute code accordingly.

1. Basic Syntax of If Else:

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

Example:

let x = 10;
if (x > 5) {
    console.log("x is greater than 5");
} else {
    console.log("x is not greater than 5");
}

Explanation:

• The condition x > 5 is true, so the message "x is greater than 5" will be logged.

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

let age = 18;
if (age < 18) {
    console.log("You are a minor");
} else if (age >= 18 && age <= 65) {
    console.log("You are an adult");
} else {
    console.log("You are a senior");
}

3. Nested If Else:

You can also nest if...else statements within each other to check for multiple conditions.

Example:

let x = 10;
let y = 20;

if (x > y) {
    console.log("x is greater than y");
} else {
    if (x < y) {
        console.log("x is less than y");
    } else {
        console.log("x is equal to y");
    }
}

Explanation:

• First, it checks if x > y. If false, it checks if x < y. If false, it concludes that x is equal to y.

4. Ternary Operator (Shortcut for If Else):

The ternary operator provides a more concise way of writing if...else statements. It’s used for simple conditions.

Syntax:

condition ? expressionIfTrue : expressionIfFalse;

Example:

let age = 18;
let result = age >= 18 ? "Adult" : "Minor";
console.log(result); // "Adult"

Explanation:

• If the condition age >= 18 is true, "Adult" is assigned to result, otherwise "Minor" is assigned.

Conclusion:

• if...else allows you to control the flow of code based on conditions.
• else if helps you handle multiple conditions.
• Nested if...else enables deeper decision-making logic.
• The ternary operator provides a shorter form for simple conditions.