javascript - using apply to pass in an object for the this keyword -


I'm trying to teach myself Javascript, but I think it's stuck on a basic basis. My reference book says:

" This can be applied to pass in an object to indicate the keyword."

I start with: 

  var a = 50; Var foo = function () {return.a; }

When I do foo () , then I would like 50 then I apply Try as follows: 

  foo.apply ({a: "blah"});

When I do foo () again, I still get 50 and blah was not as expected.

It appears that apply was not successful in the keyword {a: "blah"} objects .

I am almost certain that I am misunderstood what can help you with explanation?

apply () method does not modify function by any means; It only makes a function call with the specified it .

You can use bind () to create a new function, which always calls the original with the specified this : 

  var myFoo = foo.bind ({a: 'blah'}); MyFoo ();

-

Comments

Post a Comment

Popular posts from this blog

sqlite3 - UPDATE a table from the SELECT of another one -

I have the first table article where some data is missing. In the table, articles_tmp I have a part of the missing data. So I want to update the articles. Where the path path is data in articles_tmp.path where the path is not zero . With SQLite , it does not work: update article SET path = (SELECT at.path FROM Articles_tmp as AS, WHERE at.article_id = a.id and a.asp, the text is in the form and not on. It has been transmitted) where the path is null MS Access Along with, it works fine: Update Articles Join the Inner Articles at articles_tmp articles.id = articles_tmp.id SETP articles.path = articles_tmp.path Can anyone help? Sin CE SQL Server Syntax, which I provided, was not working, here this solution With whom I have come. A little modification of your original query, but with my "correlation" suggestion added. There is a SQL Bella for this: Here is the code: update article SET path = (SELECT path from articles_tmp AS T WHERE t.id
Read more

c# - Showing a SelectedItem's Property -

So I have enabled a rightclick option for my DataGrid. I want to display the only chosen property but it is not behaving like what I would like it to display my name and additional. Public category Paymentinfo {public int PaymentNo {get; Set; } Public string date {get; Set; } Public Double Pay {get; Set; } Public Double Principle {get; Set; } Public Double Interest {get; Set; } Public Double Balance {Received; Set; }} Private Zero MenuItem_OnClick (Object Sender, RoutedEventArgs e) {MessageBox.Show (AmortGrid.SelectedItem.ToString ()); } I'm trying to apply it without using a View Module! If I place a breakpoint where the messagebox and the recipient place it on selected ITEM, then this property will display the payment. A date-payment-principle-interest-balance is the only value that needs payment. Was hoping that it would be something like this MessageBox.Show (AmortGrid.SelectedItem.PaymentNo.ToString ()); When you call ToString () So you get the class typ
Read more

javascript - Render HTML after each iteration in loop -

I'm trying to gradually increase the font size of text on a web page. The code works in my place, although the new HTML / CSS does not render after every iteration of the loop and when all this is done, then display only the text of 100 px size. To see the text as if it is slowly zooming, I need to do this JavaScript is down because it is being used from a different file here is what I have ... < Pre> & lt; P class = "game-title" style = "font-size: 50px" & gt; Test & lt; / P & gt; Function sleep (milliseconds) {var start = new date (). GetTime (); For (var i = 0; i & lt; 1e7; i ++) {if ((new date). GetTime () - start) & gt; Milliseconds {break; CSS ('font-size', 'parseInt ($ (' game-title '). CSS (' font-size ')) + 1 + "pixels"); } While (parasont ($ ('# text'). Css ('font-size')) & lt; = 100) {sleep (1000); IncreaseSize (); Using CSS: Use of jQuery (sample):
Read more