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Pranay Rebeyro
Pranay Rebeyro

Posted on • Edited on

Conditional Statements in JavaScript

#javascript #beginners #programming #tutorial

Conditional Statements
Conditional statements allow JavaScript to execute different blocks of code based on whether a condition is true or false.

if statement

if - The if statement executes a block of code only if the condition is true.

let age = 20;

if (age >= 18) {
    console.log("Eligible to vote");
} //Output: Eligible to vote
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if else statement

  1. if...else - Use if...else when you want one block of code to run if the condition is true and another block if it's false. 
let age = 16;

if (age >= 18) {
    console.log("Eligible to vote");
} else {
    console.log("Not eligible to vote");
} // Output: Not eligible to vote
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if elif statement

  1. if...else if...else - Use this when you have multiple conditions to check. 
let marks = 85;

if (marks >= 90) {
    console.log("Grade A");
} else if (marks >= 75) {
    console.log("Grade B");
} else if (marks >= 50) {
    console.log("Grade C");
} else {
    console.log("Fail");
} // Output: Grade B
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switch statement

  1. switch statement - The switch statement is used when you have many possible values for one variable. 
let day = 3;

switch (day) {
    case 1:
        console.log("Monday");
        break;

    case 2:
        console.log("Tuesday");
        break;

    case 3:
        console.log("Wednesday");
        break;

    default:
        console.log("Invalid Day");
} // Output: Wednesday

// Important: The break statement stops the execution after the matching case.We must compulsory to use break statement because if you don't use break, JavaScript will continue executing the next cases even the output is correct.
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Nested if statement

  1. Nested if statement - You can also write an if statement inside another if. 
let age = 20;
let hasLicense = true;

if (age >= 18) {
    if (hasLicense) {
        console.log("You can drive.");
    }
} // Output: You can drive.
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Ternary Operator

  1. Ternary Operator - A conditional expression used to choose between two values based on a condition.

The ternary operator (?:) is used to write simple conditions in a single line. It is commonly used instead of a simple if...else statement when assigning a value.

let isLoggedIn = true;
let systemMessage = isLoggedIn ? "Welcome back!" : "Please log in.";

console.log(systemMessage); // Outputs: Welcome back!
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Top comments (2)

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jonrandy profile image
Jon Randy 🎖️ • • Edited

The conditional (ternary) operator is neither a conditional statement, nor a shortcut for if else.

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pranay_7424 profile image
Pranay Rebeyro •

Thanks for the correction I've updated the article to make the explanation more accurate. Really appreciate your feedback