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How can I determine if a variable is 'undefined' or 'null'?
...enceError and break execution if variable is not defined or referred to at all in the code, using typeof is safer.
– Mani Gandham
Jun 15 '14 at 9:49
59
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jQuery Validate - Enable validation for hidden fields
...ry, this could break an existing
setup. In the unlikely case that it actually does, you can fix it by
setting the ignore-option to “[]” (square brackets without the
quotes)."
To change this setting for all forms:
$.validator.setDefaults({
ignore: [],
// any other default option...
Summarizing multiple columns with dplyr? [duplicate]
...
The dplyr package contains summarise_all for this aim:
library(dplyr)
df %>% group_by(grp) %>% summarise_all(list(mean))
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#>...
How to get JQuery.trigger('click'); to initiate a mouse click
... if one of the hrefs on the <a tag is '#', that would do it. <a normally redirects to a different URL. You must stop it with ev.preventDefault() and ev.stopPropagation() before your click handler returns. OR, use some other tag besides <a; you can attach click handlers to anything that's...
How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)
My version of node is always v0.6.1-pre even after I install brew node and NVM install v0.6.19.
28 Answers
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How to define different dependencies for different product flavors
I am converting one of my apps to Gradle and would like to use the new build flavor features to have a paid and a free ad based flavor.
...
How can I run a PHP script in the background after a form is submitted?
...f subscribers and send out 150+ emails. (The emails are being sent individually as requested by the system administrators of our email server because of mass email policies.)
...
How to return 2 values from a Java method?
...
You can use SimpleEntry<type_of_value_1, type_of_value_2> from java.util.AbstractMap.SimpleEntry and use it with getKey() to get object 1 and getValue() to get object 2
– Crystalonics
Apr 28 '16 at 18:03
...
Check whether user has a Chrome extension installed
...f there is an error while loading this file, said network stack error will appear in the console with no possibility to silence it. When Chromecast used this method, it caused quite a bit of controversy because of this; with the eventual very ugly solution of simply blacklisting very specific errors...
Reading a plain text file in Java
...
I'd also recommend you download and read this wonderful (yet free) book called Thinking In Java
In Java 7:
new String(Files.readAllBytes(...))
(docs)
or
Files.readAllLines(...)
(docs)
In Java 8:
Files.lines(..).forEach(...)
(docs)
...