The second one is always the better choice for readability, and the performance benefit (if one even exists) would be marginal using a switch statement. The < / > operators are probably an instruction or two of native code, and…
‘${fName}’ is treated as a regular string. You’re supposed to use string templates: document.write(`${fName}`); 0 solved ES6 String Substitution does not work
If it is about the longest possible matching (sub)string, thus the most specific one, the task actually can be solved pretty easy. sort the array descending by each of its string-item’s length property. Iterate the array … for each string…
This is a list of all falsy values in javascript: false 0 ” or “” null undefined NaN Only the String ” is a falsy value, meaning that it is an empty string. ‘0’ is a string with content so…
Introduction In ES6, the concept of truthiness is an important concept to understand. It is a concept that determines whether a value is considered true or false. In this article, we will discuss whether 0 is considered true in ES6.…
You may use the following regex pattern: (?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) \d{1,2}(?: \d{4})? var dates = [“Nov 29 2019”, “abc 0 May 30 2020”, “ddd Apr 3 2021 efg”, “0 Jan 3 hellodewdde deded”, “Green eggs and ham”]; var months = “(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)”; var…
Here you go. It’s just the way Symbol’s toString() is implemented (and in turn gets printed in console), not any special syntax. 0 solved Understanding members of Symbol – function constructor
Use map with filter: let posts = [{ “id”: 101, “title”: “Some post title” }, { “id”: 102, “title”: “Some Another post title” }, { “id”: 103, “title”: “Some Best post title ever” } ] let reviews = [{ “postId”:…
You can’t use variables (let, var, const) within classes like that. You need to write a constructor and within the constructor, you can define what attributes the class should have, e. g. color. For methods, you simply write the methods…
I mean opA is a function, so why not opA()? Because opA is a reference to the function itself. The promise will use that reference to execute that function at a later time. Alternatively, opA() executes the function (without any…
The ES6 spread operator can be used on Objects to ‘spread’ their values into another object to create a clone of that object. It is similar in concept to using Object.assign Sample const x = { a : 1 };…
You can use jQuery along with React and ES6. At the end of the day, it’s all JavaScript. However, if you structure your code correctly with React components, you should not need to use jQuery selectors to make any changes…
You can use .map(), .concat() and Object.assign() methods to get the resultant array: let data = [ {Name: ‘Color’, Data:[{Id: 1, Name: ‘Red’}, {Id: 2, Name: ‘Yellow’}, {Id: 3, Name: ‘Blue’}, {Id: 4, Name: ‘Green’}, {Id: 7, Name: ‘Black’}]}, {Name:…
You can easily group by name to get what you need. Below is a quite general function to group any array of objects to a Map, by specified property. Then simply make it an array and you’re done function group(arr,…
var sales = [ { order_id: 138, price: 25, }, { order_id: 138, price: 30, }, { order_id: 139, price: 15, }, { order_id: 131, price: 25, }, ]; var buf = {} sales.map(obj => { if(buf[obj.order_id]) { buf[obj.order_id].price +=…