properties - What does this line of javascript mean? -

-

I hope to learn some things in retina.js Opened, but I've been stumped on the first line.

var root = (typeof export === 'undefined'? Window: export);

What does this line actually do?

forward down,

function retina () {} root.Retina = Retina;

How was the retinal property established without root before it was defined?

typeof is the operator, which is used on a variable, Which is not defined at all, will still give the result in the value 'undefined' . Expression: 

  (typeof export === 'undefined'? Window: export)

Checks whether export window (global object in the browser), and if this happens, then the result of export (exporting) A standard name for things [type] from module - see) As a result, the route is assigned.

If you were thinking about conditional operators, 

  var d = a? B: C;  

  is equal to or equal to var d; If (A) {D = B; } And {d = c; }

As root.Retina = Retina; For JavaScript, like all other properties in JavaScript, there is no need to declare it and there is no facility to declare it.


Comments

Post a Comment

Popular posts from this blog

Editing Python Class in Shell and SQLAlchemy -

-
I am working on the terminal on a shell script after this tutorial SQLAlchemy tutorial. I need to type gt; & Gt; & Gt; Sqlalchemy import column, integer, string & gt; & Gt; & Gt; Class user (base): __tablename__ = 'users' id = column (integer, primary_key = true) name = column (string) absolute name = column (string) password = column (string) def __repr __ (self): return "& lt ; User (name = '% s', absolute name = '% s', password = '% s') & gt; "% (Self.name, self.fullname, self.password) After the problem I have typed the password = column (string) I hit twice and changed .... >> I then took everything back but then an error was thrown because the class already exists ... I am not completely sure how to fix it. How do I open that slip in the shell script and edit it (Add DF to DRR) The error thrown below: / user / giripeters / TFSQLLX / Lib / python2.7 / site-packages / sqlalchemy / ext / decla...
Read more

uislider - In a MATLAB GUI, how does one implement a continuously varying slider from a GUIDE created .m file? -

-
I am trying to create a GUI with a plot and a slider. The slider should be described as continuously and output. I have a problem with this explanation that the uicontrol object is programmatically created, on the contrary, I want to know that in the last three instances, to complete the same thing done according to the program What can be added to a GUI file that is created. The code is down, and I have marked the (wrong) code that is provided by some of the above examples. Thanks a lot for any help! This slider function sets P1_slider_Callback (hObject, eventdata, handle) (handle, dragon, 'string', num2str (get (hObject, 'value'), 3)) PlottheData_Callback ( HOBject, EventData, Handle)% "PlotHeadata" is a button that creates the data slider based on the value of P1_slider%, and I think that here "p1_slider_CreateFcn" (hObject, eventdata, handle) needs to be assembled (HOBJECT, 'BackgroundRoller'), (0, 'Default UITTACKBACK MANDROLLE...
Read more

python - Django Custom Admin Block For center of admin -

-
So I'm overriding change_form.html to add some features to my admin page. Everything is working fine, I am currently using the "after_field_sets" block, but I want to put content between this field in my field_sets, not after that. I set the field above and below the new set, but I can not understand which block is used to put them in the middle of field sets. There is a list of all blocks text "> After reading the code referenced by the link you posted I reached the conclusion that the block you are looking for does not exist in it called content There is a block but more than just that "main content" but this is not the end of the world, you still have to make the template IR order to "make some space" for your content. Remember Padit can. And very important, keep in mind that you can css and js edit files as well.
Read more