| 1 | How do you conditionally render one of several possible components cleanly, without a long chain of if statements? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Advanced |
| 2 | How do you show different content in React depending on a condition? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Beginner |
| 3 | How do you render a list of items in React using the map function? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Beginner |
| 4 | Why is using an array's index as a key generally considered a bad practice? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Intermediate |
| 5 | How do you render a fallback message when a list is empty? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Intermediate |
| 6 | How would you use a keyed Fragment when rendering a list of grouped elements? React › Portals & Fragments | React | Portals & Fragments | Intermediate |
| 7 | How would you conditionally apply different CSS classes based on a component's state, such as showing an active style? React › Styling in React (CSS Modules, Styled Components & Tailwind) | React | Styling in React (CSS Modules, Styled Components & Tailwind) | Advanced |
| 8 | What is a simple real world example of when useMemo actually helps a React app? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Beginner |
| 9 | What is a Fragment in React and why would you use one instead of a div? React › Portals & Fragments | React | Portals & Fragments | Beginner |
| 10 | How does the new at for control flow block work, and why does it require a track expression? Angular › New Control Flow Syntax (@if, @for & @switch) | Angular | New Control Flow Syntax (@if, @for & @switch) | Beginner |
| 11 | How would you animate a list where items can be added or removed, such as a shopping cart? React › Animation in React (Framer Motion & React Spring) | React | Animation in React (Framer Motion & React Spring) | Intermediate |
| 12 | How do you embed a JavaScript expression inside JSX? React › Components & JSX | React | Components & JSX | Intermediate |
| 13 | What is reconciliation in React, and how does it decide what actually needs to change on the screen? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Intermediate |
| 14 | How does React's reconciliation process handle components of a completely different type appearing in the same position? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Intermediate |
| 15 | Why does changing an element's key prop cause React to completely remove and recreate that element instead of just updating it? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Advanced |