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Sentry is a complete javascript debugging and monitoring tool package that allows you to track your production code. Some of the features of sentry −Record environment and usage details to recreate and fix bugsSee the error and stack trace previously only visible in user's debug console.Apply source maps automatically to convert minified, compiled, or transpiled code back to its original form.Mobile app reporting support.
The best way to catch invalid JSON parsing errors is to put the calls to JSON.parse() to a try/catch block.Examplefunction parseJSONSafely(str) { try { return JSON.parse(str); } catch (e) { console.err(e); // Return a default object, or null based on use case. return {} } }
The text/javascript content type is obsolete. This was used in the early days of Html.application/x-javascript was an experimental content type(hence the x-). You should not be using this in your application.The correct content type to use in browsers is application/javascript. This helps browsers accept the content as js code.
Pluck has been removed from lodash 4. This is because it did the same thing as a map.As a replacement, you can use the map function in the following way −Exampleimport _ from 'lodash' const objects = [{ 'a': 1 }, { 'a': 2 }]; console.log(_.map(objects, 'a'))OutputThis will give the output −[1, 2]
Pluck has been removed from lodash 4. This is because it did the same thing as a map.As a replacement, you can use the map function in the following way −Exampleimport _ from 'lodash' const objects = [{ 'a': 1 }, { 'a': 2 }]; console.log(_.map(objects, 'a'))This will give the output −Output[1, 2]
JavaScript used to be single-threaded. It runs using what is called an event loop.The Event Loop has one simple job — to monitor the Call Stack and the Callback Queue. If the Call Stack is empty, it will take the first event from the queue and will push it to the Call Stack, which effectively runs it.JS in browsers doesn't support multithreading in the event loop as it is not needed for 99.999% of the websites. The event loop handles everything seamlessly.For the remaining apps, devs can use web workers. Web Workers are a simple means for web content to ... Read More
To test if a letter in a string is uppercase or lowercase using javascript, you can simply convert the char to its respective case and see the result.Examplefunction checkCase(ch) { if (!isNaN(ch * 1)){ return 'ch is numeric'; } else { if (ch == ch.toUpperCase()) { return 'upper case'; } if (ch == ch.toLowerCase()){ return 'lower case'; } } } console.log(checkCase('a')) console.log(checkCase('A')) console.log(checkCase('1'))OutputThis will give the output −lower case upper case ch is numeric
JS frameworks are JavaScript code libraries that have pre-written code to use for routine programming features and tasks. It is literally a framework to build websites or web applications around.For example, in plain JS, you have to manually update the DOM using DOM APIs for setting styles updating content, etc.JS frameworks can help automate this repetitive task using features like 2-way binding and templating.Frameworks have their own way of doing things. For example, Angular is a popular JS framework that comes with many features like dependency injection, routing, etc and has its own way of building an application using it. ... Read More
You can use 2 properties, clientHeight and offsetHeight to get the height of the div.clientHeight includes padding of the div.offsetHeight includes padding, scrollBar, and borders of the div.ExampleFor example, if you have the following HTML −You can get the height using −const height = document.querySelector('#myDiv').offsetHeight console.log(height)OutputThis will give the output −400
To get a subset of object's properties and create a new object out of those properties, use object destructuring and property shorthand. For example, You have the following object −Exampleconst person = { name: 'John', age: 40, city: 'LA', school: 'High School' }And you only want the name and age, you can create the new objects using −const {name, age} = person; const selectedObj = {name, age}; console.log(selectedObj);OutputThis will give the output −{ name: 'John', age: 40 }