Transforming a Javascript iterable into an array

by

You are looking for the new Array.from function which converts arbitrary iterables to array instances:

var arr = Array.from(map.entries());

It is now supported in Edge, FF, Chrome and Node 4+.

Of course, it might be worth to define map, filter and similar methods directly on the iterator interface, so that you can avoid allocating the array. You also might want to use a generator function instead of higher-order functions:

function* map(iterable) {
    var i = 0;
    for (var item of iterable)
        yield yourTransformation(item, i++);
}
function* filter(iterable) {
    var i = 0;
    for (var item of iterable)
        if (yourPredicate(item, i++))
             yield item;
}

More Related Contents:

  1. setState doesn’t update the state immediately
  2. Does ES6 introduce a well-defined order of enumeration for object properties?
  3. What does “this” refer to in arrow functions in ES6?
  4. Private properties in JavaScript ES6 classes
  5. Why can I change a constant object in javascript
  6. Call static methods from regular ES6 class methods
  7. Defer execution for ES6 Template Literals
  8. ECMAScript 6 features available in Node.js 0.12
  9. ES6: Conditional & Dynamic Import Statements
  10. JS/ES6: Destructuring of undefined
  11. How to know when all Promises are Resolved in a dynamic “iterable” parameter?
  12. ES6 classes : what about instrospection?
  13. Do I need require js when I use babel?
  14. What is an “internal slot” of an object in JavaScript?
  15. Do __proto__ and Object.getPrototype of expose exactly the same functionality?
  16. ES6 destructuring object assignment function parameter default value
  17. Why es6 react component works only with “export default”?
  18. What does the arrow function with a () after means? [duplicate]
  19. How to publish a module written in ES6 to NPM?
  20. Lazy getter doesn’t work in classes
  21. Why does the Promise constructor require a function that calls ‘resolve’ when complete, but ‘then’ does not – it returns a value instead?
  22. Destructuring deep properties
  23. How should I import the Spatial Illusions milsymbol library into my webpage?
  24. “unexpected token import” in Nodejs5 and babel?
  25. How to get the target of a JavaScript Proxy?
  26. Why is `throw` invalid in an ES6 arrow function?
  27. Where argument of first next() call goes? [duplicate]
  28. ES6 module scope
  29. ECMA6 generators: yield promise
  30. ES6 – declare a prototype method on a class with an import statement

Leave a Comment