Html 5 validation : Attribute ng-app is not a valid attribute of element body

Attribute 'ng-app' is not a valid attribute of element 'Body'

This is just a warning. You haven't enabled html5 in your application.That s why you are receiving this validation warnings.

Here i gave solution to rid out from this warnings.

After opened your MS VS, Select Tools->Options ->Text Editor- >HTML->Validation, Choose html5 in list, then restart your project.

If you are not find html5 in the list, you need to install html5, then do above step. Click here to down html5.

Again you are receiving such that warining, then prepend data- to the attribute name (e.g. data-ng-app, the warning lines gets disappear.

Attribute ng-app is not a valid attribute of element Div

Attribute 'ng-app' is not a valid attribute of element 'Div'

This is just a warning. You haven't enabled html5 in your application.That s why you are receiving this validation warnings.

Here i gave solution to rid out from this warnings.

After opened your MS VS, Select Tools->Options ->Text Editor- >HTML->Validation, Choose html5 in list, then restart your project.

If you are not find html5 in the list, you need to install html5, then do above step. Click here to down html5.

Again you are receiving such that warining, then prepend data- to the attribute name (e.g. data-ng-app, the warning lines gets disappear.

Validator. Pattern for only numbers in angular 4

We usually validate the form control by using Validator component from angular/forms.

formControlAge = new FormControl('',[
(control : AbstractControl) => Validators.pattern(`[0-9]+[A-Z]?`)])

count of digits after decimal points

Here we have an example to find out the number of digits that come after decimal points.

string number = "253.1258";
int length = number.Substring(number.IndexOf(".")+1).Length;

CSS colon expected in app.component.css

This is the issue i am facing right now. I will update this once i got solution.

What is Transpiling in Angular?

Compiling

is the general term for taking source code written in one language and transforming into another.

Transpiling

is a specific term for taking source code written in one language and transforming into another language that has a similar level of abstraction.

Transpiling is the process of converting the typescript into javascript (using Traceur, a JS compiler). 

Though typescript is used to write code in the Angular applications, the code is internally transpiled into javascript.