Q981. What are the placeholders from console object?
Below are the list of placeholders available from console object, 1. %o — It takes an object, 2. %s — It takes a string, 3. %d — It is used for a decimal or integer These...
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Q982. How are error boundaries handled in React v15?
**⚠️ LEGACY:** This question is only relevant for historical context. React v15 is extremely outdated (released in 2016). React v15 provided very basic support for _error...
Q983. Is it possible to add CSS to console messages?
Yes, you can apply CSS styles to console messages similar to html text on the web page. ```javascript console.log( "%c The text has blue color, with large font and red ba...
Q984. What is the purpose of render method of `react-dom`?
This method is used to render a React element into the DOM in the supplied container and return a reference to the component. If the React element was previously rendered...
Q985. What is the purpose of dir method of console object?
The `console.dir()` is used to display an interactive list of the properties of the specified JavaScript object as JSON. ```javascript const user = { name: "John", id: 1,...
Q986. What will happen if you use `setState()` in constructor?
When you use `setState()`, then apart from assigning to the object state React also re-renders the component and all its children. You would get error like this: _Can onl...
Q987. Is it possible to debug HTML elements in console?
Yes, it is possible to get and debug HTML elements in the console just like inspecting elements. ```javascript const element = document.getElementsByTagName("body")[0]; c...
Q988. Is it good to use `setState()` in `componentWillMount()` method?
**⚠️ DEPRECATED:** `componentWillMount()` has been removed in React 17+. This question is only relevant for legacy React applications. **Historical Context:** While it wa...
Q989. How do you display data in a tabular format using console object?
The `console.table()` is used to display data in the console in a tabular format to visualize complex arrays or objects. ```js const users = [ { name: "John", id: 1, city...
Q990. What will happen if you use props in initial state?
If the props on the component are changed without the component being refreshed, the new prop value will never be displayed because the constructor function will never up...