A while ago our team migrated all its code (a mid-sized AngularJS app) to JavaScript compiled using Traceur Babel. I’m now using the following rule of thumb for functions in ES6 and beyond: Use function in the global scope and for Object.prototype properties. Use class for object constructors. Use => everywhere else. Why use arrow … Read more
What It Is This is an arrow function. Arrow functions are a short syntax, introduced by ECMAscript 6, that can be used similarly to the way you would use function expressions. In other words, you can often use them in place of expressions like function (foo) {…}. But they have some important differences. For example, … Read more
That is a curried function First, examine this function with two parameters … const add = (x, y) => x + y add(2, 3) //=> 5 Here it is again in curried form … const add = x => y => x + y Here is the same1 code without arrow functions … const add … Read more
tl;dr: No! Arrow functions and function declarations / expressions are not equivalent and cannot be replaced blindly. If the function you want to replace does not use this, arguments and is not called with new, then yes. As so often: it depends. Arrow functions have different behavior than function declarations / expressions, so let’s have … Read more
You must wrap the returning object literal into parentheses. Otherwise curly braces will be considered to denote the function’s body. The following works: p => ({ foo: ‘bar’ }); You don’t need to wrap any other expression into parentheses: p => 10; p => ‘foo’; p => true; p => [1,2,3]; p => null; p … Read more
Async arrow functions look like this: const foo = async () => { // do something } Async arrow functions look like this for a single argument passed to it: const foo = async evt => { // do something with evt } Async arrow functions look like this for multiple arguments passed to it: … Read more