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Checking if a variable is not nil and not zero in ruby
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From Ruby 2.3.0 onward, you can combine the safe navigation operator (&.) with Numeric#nonzero?. &. returns nil if the instance was nil and nonzero? - if the number was 0:
if discount&.nonzero?
# ...
end
Or p...
How to grab substring before a specified character jQuery or JavaScript
... +1, I think this is a reasonable method, but I took a hint from this and went with addy.split(',', 1)[0]
– antak
Aug 8 '14 at 5:39
3
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jQuery loop over JSON result from AJAX Success?
On the jQuery AJAX success callback I want to loop over the results of the object. This is an example of how the response looks in Firebug.
...
How do I change the cursor between Normal and Insert modes in Vim?
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A popular option to indicate switching to and from Insert mode is
toggling the cursorline option, which is responsible for whether
the current screen line is highlighted (see :help cursorline):
:autocmd InsertEnter,InsertLeave * set cul!
or, alternatively:
:autocmd Inse...
Proper usage of Java -D command-line parameters
..., what is the proper way of writing the command-line and then accessing it from code?
3 Answers
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How much of a git sha is *generally* considered necessary to uniquely identify a change in a given c
...arse --short for the shortest and yet unique SHA1.
See "git get short hash from regular hash"
git rev-parse --short=4 921103db8259eb9de72f42db8b939895f5651489
92110
As you can see in my example the SHA1 has a length of 5 even if I specified a length of 4.
For big repos, 7 isn't enough sinc...
How can I check if a key is pressed during the click event with jQuery?
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You can easily detect the shift, alt and control keys from the event properties;
$("button").click(function(evt) {
if (evt.ctrlKey)
alert('Ctrl down');
if (evt.altKey)
alert('Alt down');
// ...
});
See quirksmode for more properties. If you want to detect other ...
How to use HttpWebRequest (.NET) asynchronously?
...chronous operation is complete. You need to at least call EndGetResponse() from this function.
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Does PowerShell support constants?
...on for defining a constant like this:
const myConst = 42
Solution taken from http://poshcode.org/4063
function Set-Constant {
<#
.SYNOPSIS
Creates constants.
.DESCRIPTION
This function can help you to create constants so easy as it possible.
It works as k...
Relative frequencies / proportions with dplyr
...2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That makes it easy to progressively roll-up a dataset.
Thus, after the summarise, the last grouping variab...