Quick recall
Object helpers are useful for inspection and copying, but most built-in copy patterns are still shallow.
JavaScript objects support descriptor-level control, computed accessors, explicit prototype creation, and different ways to check for properties.
These patterns solve different problems: recursion for self-referential logic, memoization for caching, currying for partial application, and debounce or throttle for rate control.
JavaScript regexes support pattern matching, modifiers, capture groups, and replacement operations for text processing.
JavaScript runs user code on a single main thread, but hosts like browsers and Node.js provide different APIs around that execution model.
Modern array work relies on iteration helpers, search helpers, and knowing which methods mutate the original array.
Spread expands values, rest collects remaining values, and destructuring pulls parts of arrays or objects into variables.
Strict mode opts JavaScript into safer behavior by preventing some silent mistakes and tightening runtime rules.
JavaScript testing usually starts with small unit tests, clear assertions, and selective mocking of outside dependencies.
`this` depends on how a function is called, and `call`, `apply`, and `bind` let you control that context explicitly.
Use `let` and `const` for block scope, remember that `var` is function-scoped, and know that hoisting behaves differently across them.
Accessibility in React still starts with semantic HTML, keyboard support, clear form behavior, and careful ARIA usage.