Last week, a meeting of UralJS was held in Yekaterinburg. We again gathered hundreds of developers and broke co-working - we had to install an additional monitor in the kitchen and duplicate the projector screen in order to relieve the load on the main hall.

According to tradition, there were three speakers - a freelancer, a contourist and an evil Martian. Here is what we discussed:

Nikolai Karev - this is evil

The keyword this introduces an implicit state into the application and creates dependencies within the class. Kohl's report on how to solve these problems using functional programming tools.

If you've never heard of lenses and currying, look at the link. Kohl not only explains what it is, but also gives real examples where they can be useful.

Mikhail Shatihin - Ruthless Typing

Using TypeScript as an example, Misha talks about the advantages of typing — excluding typos, predictable input parameters, autocompletion in the code editor, and disappearing tests for entire classes of errors.

Misha's report is primarily an instruction for those who want to add types to the Redux application, but do not know how. Especially for such a case, Misha drew up a typing plan and moved methodically along it, talking in detail about the syntax and instant buns for the developer.

Alexey Ivanov - React and Data: Effective ways of storing and changing the state

The story of how to optimize the work of the tree of several hundred components. If your checkboxes are set for half a second, pauses occur when entering data in the text field, and animations only interfere with normal work with the application - this report is for you.

Lesha tells how React works from the inside. This is necessary to know in order to reduce the number of inserts and recalculations - they affect the performance of the application. Lesha proceeds from simple manipulations in DevTools to more complicated ones, which by the end of the report were reduced to a laconic checklist:

Leave questions and impressions in the comments, subscribe to our channel on YouTube and, if you live nearby, join our community as listeners and speakers.

UralJS # 7

We are already preparing UralJS # 7.

Participate in the compilation of the program in the repository on Gitkhab . Just create a new issue to add your report or suggest a topic for someone. For ideas, you can vote like , and in the comments to ask questions and share useful materials on the topic.

See you in April :)