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How can I detect if a selector returns null?
...Why did you wrap 'this' inside a $() ? wouldn't 'this' in this context actually point to jQuery object ?
– Adham Atta
Mar 28 '11 at 11:25
1
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Key existence check in HashMap
...than getting the value. So it won't optimize anything to check the key actually exists before getting the value. I know it's a generalization but it can help to understand.
– Colin Hebert
Sep 2 '10 at 12:42
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Extracting specific columns from a data frame
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Using the dplyr package, if your data.frame is called df1:
library(dplyr)
df1 %>%
select(A, B, E)
This can also be written without the %>% pipe as:
select(df1, A, B, E)
share
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Qt: can't find -lGL error
I just reinstalled QtCreator, created new project ( Qt Application ) an got this after compilation:
8 Answers
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How to add a downloaded .box file to Vagrant?
...hing in the Vagrantfile. I am just using the Vagrantfile that got automatically created upon vagrant init. When i cat Vagrantfile, I don't see anything called a password or pem or anything
– Rakib
Sep 15 '15 at 12:31
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Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
I have installed MySQL server and trying to connect to it, but getting the error:
18 Answers
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Check if a value exists in ArrayList
... case because if not a CurrentAccount object may not be the same even when all their attributes have the same value. But I do agree in overriding hashcode() too.
– Javi
Dec 9 '10 at 23:51
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For..In loops in JavaScript - key value pairs
...is specific case I would assume it's slower because of the Object.entries call. I didn't run any tests though.
– Francesco Casula
Jul 9 '17 at 6:44
7
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When to use transclude 'true' and transclude 'element' in Angular?
...le the content of the element and make it available to the directive. Typically used with ngTransclude. The advantage of transclusion is that the linking function receives a transclusion function which is pre-bound to the correct scope. In a typical setup the widget creates an isolate scope, but the...
Check if list contains element that contains a string and get that element
...plement them), as I'm not familiarized with it. What I would like to, basically, is this:
12 Answers
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