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What are the precise rules for when you can omit parenthesis, dots, braces, = (functions), etc.?
...he parenthesis if there is less than two parameters passed to the method.
Now, the operator notation is a notation for method-call, which means it can't be used in the absence of the object which is being called.
I'll briefly detail the notations.
Prefix:
Only ~, !, + and - can be used in prefix...
Summarizing multiple columns with dplyr? [duplicate]
...x. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
...
How do I integrate Ajax with Django applications?
...eturn the index.html and replace all the variables as asked (you probably know all this by now).
Now let's talk about AJAX. AJAX calls are client-side code that does asynchronous requests. That sounds complicated, but it simply means it does a request for you in the background and then handles the ...
MySQL SELECT only not null values
...uld use IS NOT NULL. (The comparison operators = and <> both give UNKNOWN with NULL on either side of the expression.)
SELECT *
FROM table
WHERE YourColumn IS NOT NULL;
Just for completeness I'll mention that in MySQL you can also negate the null safe equality operator but this is not sta...
Date only from TextBoxFor()
...
Yes, as now there is the EditorFor helper and MVC2 is finalized, your solution is the way to go
– Kronos
Nov 8 '10 at 15:03
...
Random data in Unit Tests?
... counter-evidence to refute that the program works according to the spec.
Now, you can write the unit tests by hand, but it really is a mechanical task. It can be automated. All you have to do is write the spec, and a machine can generate lots and lots of unit tests that try to break your code.
I ...
Hidden features of Ruby
Continuing the "Hidden features of ..." meme, let's share the lesser-known but useful features of Ruby programming language.
...
How do I get PyLint to recognize numpy members?
...mmand. They had fixed this problem in an earlier version in an unsafe way. Now if you want them to look more carefully at a package outside of the standard library, you must explicitly whitelist it. See here.
share
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Android Studio - Ambiguous method call getClass()
...
I think it is a bug in Android Studio. As we know, Android Studio is based on the IntelliJ Platform and the existing functionality of IntelliJ IDEA Community Edition.
Google has developed it in cooperation with JetBrains. And same bug is reported to happen in IntelliJ a...
Delete files older than 15 days using PowerShell
...l be deleted), remove the switch to actually delete the files:
$old = 15
$now = Get-Date
Get-ChildItem $path -Recurse |
Where-Object {-not $_.PSIsContainer -and $now.Subtract($_.CreationTime).Days -gt $old } |
Remove-Item -WhatIf
...