Q11. How do you conditionally render components?
In some cases you want to render different components depending on some state. JSX does not render `false` or `undefined`, so you can use conditional _short-circuiting_ t...
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Q12. Why we need to be careful when spreading props on DOM elements?
When we _spread props_ we run into the risk of adding unknown HTML attributes, which is a bad practice. Instead we can use prop destructuring with `...rest` operator, so ...
Q13. How do you memoize a component?
There are memoize libraries available which can be used on function components. For example `moize` library can memoize the component in another component. ```jsx harmony...
Q14. How you implement Server Side Rendering or SSR?
React is already equipped to handle rendering on Node servers. A special version of the DOM renderer is available, which follows the same pattern as on the client side. `...
Q15. What is a switching component?
A _switching component_ is a component that renders one of many components. We need to use object to map prop values to components. For example, a switching component to ...
Q16. Why should component names start with capital letter?
If you are rendering your component using JSX, the name of that component has to begin with a capital letter otherwise React will throw an error as an unrecognized tag. T...
Q17. Are custom DOM attributes supported in React v16?
**Note:** This question references React v16, which is outdated. The information below applies to React 16+, including current versions (React 18/19). Yes. Starting with ...
Q18. How to loop inside JSX?
You can simply use `Array.prototype.map` with ES6 _arrow function_ syntax. For example, the `items` array of objects is mapped into an array of components: ```jsx harmony...
Q19. How do you access props in attribute quotes?
React (or JSX) doesn't support variable interpolation inside an attribute value. The below representation won't work: ```jsx harmony ``` But you can put any JS expression...
Q20. How to conditionally apply class attributes?
You shouldn't use curly braces inside quotes because it is going to be evaluated as a string. ```jsx harmony ``` Instead you need to move curly braces outside (don't forg...