Q2471. What are the differences between for...of and for...in statements?
Both for...in and for...of statements iterate over js data structures. The only difference is over what they iterate: 1. for..in iterates over all enumerable property key...
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Q2472. What is the purpose of unmountComponentAtNode method?
This method is available from react-dom package and it removes a mounted React component from the DOM and clean up its event handlers and state. If no component was mount...
Q2473. How do you define instance and non-instance properties?
The Instance properties must be defined inside of class methods. For example, name and age properties defined inside constructor as below, ```javascript class Person { co...
Q2474. What are the limitations with HOCs?
Higher-order components come with a few caveats apart from its benefits. Below are the few listed in an order, 1. **Don’t use HOCs inside the render method:** It is not r...
Q2475. What is the difference between isNaN and Number.isNaN?
1. **isNaN**: The global function `isNaN` converts the argument to a Number and returns true if the resulting value is NaN. 2. **Number.isNaN**: This method does not conv...
Q2476. How to debug forwardRefs in DevTools?
**React.forwardRef** accepts a render function as parameter and DevTools uses this function to determine what to display for the ref forwarding component. For example, If...
Q2477. How to invoke an IIFE without any extra brackets?
Immediately Invoked Function Expressions(IIFE) requires a pair of parenthesis to wrap the function which contains set of statements. ```js (function (dt) { console.log(dt...
Q2478. Is it good to use arrow functions in render methods?
Yes, You can use. It is often the easiest way to pass parameters to callback functions. But you need to optimize the performance while using it. ```javascript class Foo e...
Q2479. Is that possible to use expressions in switch cases?
You might have seen expressions used in switch condition but it is also possible to use for switch cases by assigning true value for the switch condition. Let's see the w...
Q2480. How do you say that state updates are merged?
When you call setState() in the component, React merges the object you provide into the current state. For example, let us take a facebook user with posts and comments de...