arrow-functions

Arrow functions in ES6 do not have an arguments property and therefore arguments.callee will not work and would anyway not work in strict mode even if just an anonymous function was being used. Arrow functions cannot be named, so the named functional expression trick can not be used. So... How does one write a recursive arrow function? That is an arrow function that recursively calls itself based on certain conditions and so on of-course? Writing a recursive function without naming it is a problem that is as old as computer science itself (even older, actually, since λ-calculus predates

I've found on the internet about both names, arrow functions and fat arrow functions but no information about what is different between them. Are there any differences? Such a question requires a bit of explanation... ECMAScript 5 In ES5 specification, there were no arrow functions at all. It was then common to use traditional function expressions like so: // Example n°1 var myFunction = function () { return 'Hello!'; }; // Example n°2 var obj = { myFunction: function () { return 'Hello!'; } }; // Example n°3 var arr = ['foo', 'bar']; arr.map(function (item) { return 'Hello, ' + item + '!'; };

This question already has an answer here: Official information on `arguments` in ES6 Arrow functions? 2 answers I don’t know whether arrow functions bind arguments to a lexical scope or not. Take a look at this example (the same concept can be used for this ): var b = function() { return () => console.log(arguments); }; b(1,2,3)(4,5,6); // different result of chrome vs FF. When I run this on Chrome, I get [1,2,3] , but on Firefox, I get [4,5,6] . What’s going on? From the spec : Any reference to arguments , super , this , or new.target within an ArrowFunction must resolve to a binding in a

I know that 'this' in JavaScript has a different meaning than in in TypeScript, as per this article 'this' in TypeScript . I have the following code in JavaScript used to create a thicker stroke on the selected node, and give all other nodes a smaller stroke. node.on('click', function (d) { d3.selectAll('circle').attr('stroke-width', 1.5); d3.select(this).select('circle').attr('stroke-width', 5); }) In TypeScript I have this.node.on('click', (d:any) => { this.node.selectAll('circle').attr('stroke-width', 1.5); [this is where I need help].select('circle').attr('stroke-width', 5); } Gerardo

In D3.js v4, when registering an event listener through a traditional callback function, this references the current DOM element: d3.select("div").on('mouseenter', function() { d3.select(this).text("Yay"); }); ES6 offers arrow functions, which IMHO make D3.js code a lot more readable because they are very concise. However, traditional callbacks cannot blindly be replaced with arrow functions: d3.select("div").on('mouseenter', () => { d3.select(this); // undefined }); The article " On D3 and Arrow Functions " gives a very good explanation of why this is not bound as expected. The article

This question already has an answer here: Methods in ES6 objects: using arrow functions 4 answers How does the “this” keyword in Javascript act within an object literal? [duplicate] 4 answers I am trying to understand arrow functions in ECMAScript 6. This is the definition I came across while reading: Arrow functions have implicit this binding, which means that the value of the this value inside of an arrow function is aways the same as the value of this in the scope in which the arrow function is defined! According to the definition, I believe this for an arrow function should contain the