JavaScript Switch Statements

Master switch statements for handling multiple conditions efficiently and learn modern switch patterns

35 min•By Priygop Team•Last updated: Feb 2026

Switch Statement Fundamentals

Switch statements provide an alternative to if...else chains when you need to compare a single value against multiple possible values. They are more readable and often more efficient than long if...else chains.

Basic Switch Examples

Example

// Basic switch statement
let day = 'Monday';

switch (day) {
    case 'Monday':
        console.log('Start of the work week');
        break;
    case 'Tuesday':
        console.log('Second day of the week');
        break;
    case 'Wednesday':
        console.log('Middle of the week');
        break;
    case 'Thursday':
        console.log('Almost Friday');
        break;
    case 'Friday':
        console.log('TGIF!');
        break;
    case 'Saturday':
    case 'Sunday':
        console.log('Weekend!');
        break;
    default:
        console.log('Invalid day');
}

// Switch with numbers
let grade = 85;

switch (true) {
    case grade >= 90:
        console.log('Grade: A');
        break;
    case grade >= 80:
        console.log('Grade: B');
        break;
    case grade >= 70:
        console.log('Grade: C');
        break;
    case grade >= 60:
        console.log('Grade: D');
        break;
    default:
        console.log('Grade: F');
}

// Switch with expressions
let userType = 'premium';
let discount = 0;

switch (userType) {
    case 'admin':
        discount = 100;
        break;
    case 'premium':
        discount = 25;
        break;
    case 'regular':
        discount = 10;
        break;
    case 'guest':
        discount = 5;
        break;
    default:
        discount = 0;
}

console.log(`Discount: ${discount}%`);

// Switch without break (fall-through)
let month = 2;
let daysInMonth;

switch (month) {
    case 1:
    case 3:
    case 5:
    case 7:
    case 8:
    case 10:
    case 12:
        daysInMonth = 31;
        break;
    case 4:
    case 6:
    case 9:
    case 11:
        daysInMonth = 30;
        break;
    case 2:
        daysInMonth = 28; // Simplified, ignoring leap years
        break;
    default:
        daysInMonth = 0;
}

console.log(`Days in month ${month}: ${daysInMonth}`);

Modern Switch Patterns

Example

// Modern switch patterns (2025)
// Switch with object mapping
const actionHandlers = {
    'create': (data) => console.log('Creating:', data),
    'read': (id) => console.log('Reading:', id),
    'update': (id, data) => console.log('Updating:', id, data),
    'delete': (id) => console.log('Deleting:', id)
};

function handleAction(action, ...args) {
    const handler = actionHandlers[action];
    if (handler) {
        handler(...args);
    } else {
        console.log('Unknown action:', action);
    }
}

handleAction('create', { name: 'John' });
handleAction('read', 123);
handleAction('update', 123, { name: 'Jane' });
handleAction('delete', 123);

// Switch with function calls
function getGreeting(time) {
    switch (true) {
        case time < 12:
            return 'Good morning';
        case time < 17:
            return 'Good afternoon';
        case time < 21:
            return 'Good evening';
        default:
            return 'Good night';
    }
}

const currentHour = new Date().getHours();
console.log(getGreeting(currentHour));

// Switch with complex conditions
function getShippingCost(weight, destination) {
    let baseCost = 0;
    
    // Base cost by weight
    switch (true) {
        case weight <= 1:
            baseCost = 5;
            break;
        case weight <= 5:
            baseCost = 10;
            break;
        case weight <= 10:
            baseCost = 15;
            break;
        default:
            baseCost = 20;
    }
    
    // Multiplier by destination
    let multiplier = 1;
    switch (destination.toLowerCase()) {
        case 'local':
            multiplier = 1;
            break;
        case 'domestic':
            multiplier = 1.5;
            break;
        case 'international':
            multiplier = 3;
            break;
        default:
            multiplier = 2;
    }
    
    return baseCost * multiplier;
}

console.log('Local shipping (2kg):', getShippingCost(2, 'local'));
console.log('International shipping (8kg):', getShippingCost(8, 'international'));

Practice Exercise: Switch Statements

Example

// Exercise: Build a Calculator
function calculate(operation, a, b) {
    switch (operation) {
        case '+':
            return a + b;
        case '-':
            return a - b;
        case '*':
            return a * b;
        case '/':
            if (b === 0) {
                throw new Error('Division by zero');
            }
            return a / b;
        case '**':
            return a ** b;
        case '%':
            return a % b;
        default:
            throw new Error('Unknown operation');
    }
}

// Exercise: Build a Color Theme System
function getTheme(themeName) {
    switch (themeName.toLowerCase()) {
        case 'light':
            return {
                background: '#ffffff',
                text: '#000000',
                primary: '#007bff',
                secondary: '#6c757d'
            };
        case 'dark':
            return {
                background: '#121212',
                text: '#ffffff',
                primary: '#bb86fc',
                secondary: '#03dac6'
            };
        case 'blue':
            return {
                background: '#e3f2fd',
                text: '#1565c0',
                primary: '#1976d2',
                secondary: '#42a5f5'
            };
        case 'green':
            return {
                background: '#e8f5e8',
                text: '#2e7d32',
                primary: '#388e3c',
                secondary: '#66bb6a'
            };
        default:
            return {
                background: '#ffffff',
                text: '#000000',
                primary: '#007bff',
                secondary: '#6c757d'
            };
    }
}

// Test the functions
console.log(calculate('+', 10, 5)); // 15
console.log(calculate('*', 4, 3)); // 12
console.log(calculate('/', 15, 3)); // 5

const lightTheme = getTheme('light');
const darkTheme = getTheme('dark');

console.log('Light theme:', lightTheme);
console.log('Dark theme:', darkTheme);