Prerequisite for learning Angular

Moderate knowledge of HTML, CSS, and JavaScript.

Basic Model-View-Controller (MVC) concepts.

The Document Object Model (DOM).

JavaScript functions, events, and error handling.

HTML : Most of the templates we create in angularJS is in the form of handcrafted htmls. i.e. So you must know that what are forms in html and what are tags ng-form etc.

CSS : While hand crafting template you should require css to make more attractive UI design.

DOM : Document object model and how document is created. If you have good jquery background you can easily pick up this part.

Object Oriented JavaScript: Global name space: AngularJS heavily uses javascript name space. i.e.

Object Oriented JavaScript: Inheritance: Inheritance is very important concept in JavaScript. Inheritance is heavily used in all the frameworks in JavaScript. i.e.

var Employee = function(fname) {
   this.fname =fname;
   console.log("Your first name is "+fname);
} 
var fistEmployee = new Employee("John");

var secondEmployee = new Employee("Jim");

fistEmployee.prototype.lastname = function(lname) {
      this.lname=lname;
      console.log("Your last name is "+lname);
}

So using prototype you can easily add properties on the fly.

Model View Whatever(MVW): This term is used heavily by all AngularJS developers. It is coined by Google. It is simple MVC concept.

Separation of Concern(SOC): SOC concept is heavily used in AngularJS. In angularJS all the controllers, directive, services and factories are made for SOC. It provide more lean and cleaner code. Also re usability automatically increases if you use SOC concept.

Promises : Promises are nothing but callbacks. When you call any AngularJS service it will be called asynchronously. When response is send from service callback hold the response and do the needful.

Test Driven Development : Best thing about AngularJS is you can easily write test script so that when you go home, you can easily have sound sleep.

You see this 1 hour Angular 7 tutorial video which explains everything what you need to start with Angular. If you can watch you will have a better understanding of things.

So in all you need five important pre-requisites for Angular :-

1. You need to know JavaScript in depth.You should have crystal clear concepts on Javascript closures , Javascript IIFE , prototyping and so on.
2. A good understanding of NodeJs is must and especially how to use NPM ( Node package manager).
3. You need to know typescript.
4. A good understanding of module loaders , binders , commonjs , AMD , UMD , ES5 and so on.
5. This point is not compulsory its optional. If you know VS code you can learn lot of internals of Angular. As every developer has his own favorite IDE and Editor this step is optional. I would still suggest do your first couple of practicals using VS code and then proceed with your favorite IDE.

Below is the road-map of the pre-requisites and how to learn Angular. You can start learning Angular pre-requisites from this Learn Angular Step by Step article which covers around 11 labs in depth.

And yes if you are preparing for Angular interview jobs you can check video 50 Angular Interview Questions with Answers.

The most prerequisite for learning latest Angularjs (version 5.x right now - https://angular.io/tutorial) is:

TYPESCRIPT AND SOME OOPS LIKE INHERITENCE!

Everyone knows that the basics of HTML/CSS/JS is the prerequisite of everything in web development.

Today, Many people are diving into learning angularjs without knowing or just a bit about typescript. This will make learning angular a hell of a trouble, so i thought to put my 2 cents here.

Also the top most selected answer does not emphasize on the importance of learning Typescript, it's weird.

Typescript is not known to many beginners in web development. Even it's declaration is confusing if you do not study it first.

So please start from here if you wanna learn AngularJS:

https://www.typescriptlang.org/docs/handbook/2/everyday-types.html