TypeError: Cannot set properties of undefined (setting 'name')You’re trying to set a property on something that’s undefined or null.
Fix 1: Initialize the object first
// ❌ user is undefined
let user;
user.name = 'Alice'; // TypeError!
// ✅ Initialize it
let user = {};
user.name = 'Alice';Fix 2: Nested object doesn’t exist
const data = {};
// ❌ data.user doesn't exist yet
data.user.name = 'Alice'; // TypeError!
// ✅ Create the nested object first
data.user = {};
data.user.name = 'Alice';
// ✅ Or assign all at once
data.user = { name: 'Alice' };Fix 3: Array element is undefined
const users = [];
// ❌ users[0] is undefined
users[0].name = 'Alice'; // TypeError!
// ✅ Push an object
users.push({ name: 'Alice' });