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Get type of all variables
...d, there be dragons: step carefully:
typeof(substr("abc",2,2))#a string at index 2 which is 'b' is: character
typeof(c(5L,6L,7L)) #a vector containing only integers: integer
typeof(c(NA,NA,NA)) #a vector containing only NA: logical
typeof(data.frame()) #a data.frame with n...
How to add an Access-Control-Allow-Origin header
...off2)$">
<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "*"
</IfModule>
</FilesMatch>
also in your remote CSS file, the font-face declaration needs the full absolute URL of the font-file (not needed in local CSS files):
e.g.
@font-face {
font-fa...
How do I delete rows in a data frame?
...ven by the '-' operator" -> This is a very misleading wording. Negative indexes are removed and that's it, there is no notion of complement. If you work with logical and try using - it won't work, because the complement operator for logicals is !. The complement of c(2,4,6) in the rows would rath...
What is “export default” in javascript?
...strate this line with a simple example.
Lets say we have 3 modules and an index.html:
modul.js
modul2.js
modul3.js
index.html
modul.js
export function hello() {
console.log("Modul: Saying hello!");
}
export let variable = 123;
modul2.js
export function hello2() {
console.log("Modul...
What is the dual table in Oracle?
...summarized to show the amount of storage for
the DATA extent and for the INDEX extent(s). The name, DUAL, seemed
apt for the process of creating a pair of rows from just one. 1
It may not be obvious from the above, but the original DUAL table had two rows in it (hence its name). Nowadays it on...
What is the best way to iterate over a dictionary?
.... For that, LINQ provides ElementAt which enables the following:
for (int index = 0; index < dictionary.Count; index++) {
var item = dictionary.ElementAt(index);
var itemKey = item.Key;
var itemValue = item.Value;
}
...
Java EE web development, where do I start and what skills do I need? [closed]
...
(Updated Mar 2020)
First of all, "Java EE" has since Sep 2019 been renamed to "Jakarta EE", starting with version 8. Historically, there was also the term "J2EE" which covered versions 1.2 until 1.4. The "Java EE" covered versions 5 until 8. See also Ja...
How to highlight text using javascript
...etElementById("inputText");
var innerHTML = inputText.innerHTML;
var index = innerHTML.indexOf(text);
if (index >= 0) {
innerHTML = innerHTML.substring(0,index) + "<span class='highlight'>" + innerHTML.substring(index,index+text.length) + "</span>" + innerHTML.substring(...
What does “./” (dot slash) refer to in terms of an HTML file path location?
...
./ is the the folder that the working file is in:
So in /index.htm ./ is the root directory
but in /css/style.css ./ is the css folder.
This is important to remember because if you move CSS from /index.htm to /css/style.css the path will change.
...
How to alias a table in Laravel Eloquent queries (or using Query Builder)?
...supports aliases on tables and columns with AS. Try
$users = DB::table('really_long_table_name AS t')
->select('t.id AS uid')
->get();
Let's see it in action with an awesome tinker tool
$ php artisan tinker
[1] > Schema::create('really_long_table_name', function($...