// These methods work in IE11+ thanks to core-js
const posts = ['intro', 'advanced', 'tutorial'];
 
// Array.includes (IE11 needs polyfill)
const hasIntro = posts.includes('intro'); // ✅ Works everywhere
 
// Array.find (IE11 needs polyfill)
const foundPost = posts.find(post => post.startsWith('adv')); // ✅ Works everywhere
 
// Array.findIndex (IE11 needs polyfill)
const introIndex = posts.findIndex(post => post === 'intro'); // ✅ Works everywhere

// Modern object methods work across all browsers
const blogMeta = { title: 'My Post', date: '2025-09-04' };
 
// Object.entries (IE11 needs polyfill)
Object.entries(blogMeta).forEach(([key, value]) => {
  console.log(`${key}: ${value}`); // ✅ Works everywhere
});
 
// Object.values (IE11 needs polyfill)
const values = Object.values(blogMeta); // ✅ Works everywhere
 
// Object.assign (IE11 needs polyfill)
const extendedMeta = Object.assign({}, blogMeta, { author: 'You' }); // ✅ Works everywhere

const postTitle = "How to use Core-js in your MDX blog";
 
// String.includes (IE11 needs polyfill)
const isAboutCoreJs = postTitle.includes('Core-js'); // ✅ Works everywhere
 
// String.startsWith (IE11 needs polyfill)
const isHowTo = postTitle.startsWith('How to'); // ✅ Works everywhere
 
// String.endsWith (IE11 needs polyfill)
const isAboutBlog = postTitle.endsWith('blog'); // ✅ Works everywhere

// Map and Set work in older browsers
const tagMap = new Map([
  ['javascript', 'JavaScript'],
  ['typescript', 'TypeScript'],
  ['react', 'React']
]); // ✅ Works in IE11+
 
const uniqueTags = new Set(['javascript', 'typescript', 'javascript']); // ✅ Works in IE11+

// Console output examples:
console.log('🔧 Core-js polyfills applied for: Array.includes, String.startsWith, Map');
console.log('✅ Modern browser detected - all features supported natively');