Access properties with brackets and a string:
let user = { name: "Alice", "favorite color": "blue" }
console.log(user["name"]) // "Alice"
console.log(user["favorite color"]) // "blue" (spaces in key)
let prop = "name"
console.log(user[prop]) // "Alice" (dynamic)
Use bracket notation for keys with spaces, keys stored in variables, or keys computed at runtime.