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Clojure: cons (seq) vs. conj (list)
I know that cons returns a seq and conj returns a collection. I also know that conj "adds" the item to the optimal end of the collection, and cons always "adds" the item to the front. This example illustrates both of these points:
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How to display unique records from a has_many through relationship?
...ct => "DISTINCT products.*). In the first case, ALL records are fetched and rails removes the duplicates for you. In the later case, only non-duplicate records are fetched from the db so it might offer better performance if you have a large result set.
– mbreining
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Create an array or List of all dates between two dates [duplicate]
...n a time-series, you could enumerate all the dates in the full date-range, and pick the value for a date directly from the series if it exists, or the default otherwise. For example:
var paddedSeries = fullDates.ToDictionary(date => date, date => timeSeries.ContainsDate(date)
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Is there a standard keyboard shortcut to build the current project in Visual Studio?
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Assigning the shortcut to "Build.BuildOnlyProject" command doesn't seem to work in VS2008.
Assign the shortcut to "Build.BuildSelection". If you have a solution with several projects and files open from the various projects, whatever file you are currently editing will define ...
Rails: update_attribute vs update_attributes
... send(name.to_s + '=', value)
2616: save(false)
2617: end
and now refer update_attributes and look at its code you get
# File vendor/rails/activerecord/lib/active_record/base.rb, line 2621
2621: def update_attributes(attributes)
2622: self.attributes = attribute...
how to get the last character of a string?
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An elegant and short alternative, is the String.prototype.slice method.
Just by:
str.slice(-1);
A negative start index slices the string from length+index, to length, being index -1, the last character is extracted:
"abc".slice(-1)...
How do I compare two string variables in an 'if' statement in Bash? [duplicate]
..."$s1" != "$s2" ]]
For the a contains b, use:
if [[ $s1 == *"$s2"* ]]
(and make sure to add spaces between the symbols):
Bad:
if [["$s1" == "$s2"]]
Good:
if [[ "$s1" == "$s2" ]]
share
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im...
How do I define a method in Razor?
...cality. MVC isn't the only game in town. Some folks just like simple razor and URLRewrite as MVC is a lot to do for little benefit IMO
– Jason Sebring
Oct 28 '12 at 18:00
5
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How to ignore HTML element from tabindex?
...ential focus navigation.
Watch out though that this is a HTML5 feature and might not work with old browsers.
To be W3C HTML 4.01 standard (from 1999) compliant, tabindex would need to be positive.
Sample usage below in pure HTML.
<input />
<input tabindex="-1" placeholder="NoTa...
Center image using text-align center?
... the text-align property applies to block containers, not inline elements, and img is an inline element. See the W3C specification.
Use this instead:
img.center {
display: block;
margin: 0 auto;
}
<div style="border: 1px solid black;">
<img class="center" src ="https://cd...