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![AbdelGhafour Mohie](https://uploads.teamtreehouse.com/production/profile-photos/681082/micro_28233_399512426346_3222793_n.jpg)
AbdelGhafour Mohie
1,876 PointsIn what cases should we use Designated & Convenience ?
Actually i have 2 questions:
1- So this app could perfectly run without the designated initialiser or the convenience constructor, ( i just tried it) So why did we use them? and if this app can run without them , are those methods ever be mandatory in any other case ?
2- Why did we save the data we grabbed from the blog in our system ? doesn't that just keep eating memory ?
2 Answers
![P M](https://secure.gravatar.com/avatar/46cd5a33cc0a3e88c16e3bfb28270fed?s=96&d=https%3A%2F%2Fecs-static.teamtreehouse.com%2Fassets%2Fcontent%2Fdefault_avatar-445fbbabfc8dc9188fb5967fe43322ee0c3e0dd1e10f378bf8343784af5a13eb.webp&r=pg)
P M
7,320 PointsIf you will use them (call them in your code), they are mandatory. If not - they are not. It's much cleaner to use them than to have lots of nested initialisers all over your code.
If you have no data, how would you display it? Even the web page you're looking at now is saved in your computer's RAM first before it shows on the screen. Same with the data from the blog, first you grab it so you can manipulate it locally, then display it.
![AbdelGhafour Mohie](https://uploads.teamtreehouse.com/production/profile-photos/681082/micro_28233_399512426346_3222793_n.jpg)
AbdelGhafour Mohie
1,876 PointsThank You. so using them is just more of an organising thing.