JavaScript Online Compiler | Free Online Compiler

JavaScript Code

// JavaScript Demo
// Edit this code and click Run

// Setup page
document.body.style.fontFamily = 'Arial, sans-serif';
document.body.style.padding = '20px';
document.body.style.background = '#f5f5f5';

// Create container
var container = document.createElement('div');
container.style.cssText = 'max-width: 500px; margin: 0 auto; background: white; padding: 30px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.1);';

// Title
var title = document.createElement('h1');
title.textContent = 'JavaScript Demo';
title.style.cssText = 'color: #333; text-align: center; margin-bottom: 30px;';
container.appendChild(title);

// Counter section
var counterSection = document.createElement('div');
counterSection.style.cssText = 'background: #f9f9f9; padding: 20px; border-radius: 8px; text-align: center; margin-bottom: 20px;';

var count = 0;
var countDisplay = document.createElement('h2');
countDisplay.textContent = 'Count: 0';
countDisplay.style.color = '#4CAF50';
counterSection.appendChild(countDisplay);

var btnContainer = document.createElement('div');
btnContainer.style.marginTop = '15px';

var btnMinus = document.createElement('button');
btnMinus.textContent = '-';
btnMinus.style.cssText = 'padding: 10px 25px; font-size: 18px; margin: 5px; cursor: pointer;';
btnMinus.onclick = function() {
    count--;
    countDisplay.textContent = 'Count: ' + count;
};

var btnReset = document.createElement('button');
btnReset.textContent = 'Reset';
btnReset.style.cssText = 'padding: 10px 25px; font-size: 18px; margin: 5px; cursor: pointer; background: #f44336; color: white; border: none; border-radius: 4px;';
btnReset.onclick = function() {
    count = 0;
    countDisplay.textContent = 'Count: ' + count;
};

var btnPlus = document.createElement('button');
btnPlus.textContent = '+';
btnPlus.style.cssText = 'padding: 10px 25px; font-size: 18px; margin: 5px; cursor: pointer;';
btnPlus.onclick = function() {
    count++;
    countDisplay.textContent = 'Count: ' + count;
};

btnContainer.appendChild(btnMinus);
btnContainer.appendChild(btnReset);
btnContainer.appendChild(btnPlus);
counterSection.appendChild(btnContainer);
container.appendChild(counterSection);

// Input section
var inputSection = document.createElement('div');
inputSection.style.cssText = 'background: #f9f9f9; padding: 20px; border-radius: 8px;';

var inputLabel = document.createElement('h3');
inputLabel.textContent = 'Greeting';
inputLabel.style.marginBottom = '15px';
inputSection.appendChild(inputLabel);

var input = document.createElement('input');
input.type = 'text';
input.placeholder = 'Enter your name';
input.style.cssText = 'width: 100%; padding: 12px; font-size: 16px; border: 2px solid #ddd; border-radius: 5px; margin-bottom: 10px;';

var greeting = document.createElement('p');
greeting.style.cssText = 'font-size: 18px; color: #4CAF50; font-weight: bold; min-height: 25px;';

input.oninput = function() {
    if (input.value) {
        greeting.textContent = 'Hello, ' + input.value + '!';
    } else {
        greeting.textContent = '';
    }
};

inputSection.appendChild(input);
inputSection.appendChild(greeting);
container.appendChild(inputSection);

document.body.appendChild(container);

console.log('JavaScript loaded successfully!');

Output

JavaScript Compiler