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What is process.env.PORT in Node.js?
what is process.env.PORT || 3000 used for in Node.js? I saw this somewhere:
4 Answers
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Is it valid to have a tag inside another tag?
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Yes, since a website is generally divided into one or more sections, use it as long as you feel it describes the structure. A layout can have 1 or even tens of SECTION elements, just know that it is NOT a DIV replacement :)
DIVs are still used and recommended (usually for gro...
What is the difference between include and extend in Ruby?
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What you have said is correct. However there is more to it than that.
If you have a class Klazz and module Mod, including Mod in Klazz gives instances of Klazz access to Mod's methods. Or you can extend Klazz with Mod giving the class Klazz access...
Difference between pre-increment and post-increment in a loop?
Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?
22 Answers
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Rails :dependent => :destroy VS :dependent => :delete_all
...e is an instantiation of all of your children. So, if you can't destroy it or if each has their own :dependent, its callbacks can be called.
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How do I include related model fields using Django Rest Framework?
...assroom
depth = 1
However, that will only include relationships for forward relationships, which in this case isn't quite what you need, since the teachers field is a reverse relationship.
If you've got more complex requirements (eg. include reverse relationships, nest some fields, but no...
Running multiple commands in one line in shell
...direct the output of a command into another command. What you are looking for is && operator to execute the next command only if the previous one succeeded:
cp /templates/apple /templates/used && cp /templates/apple /templates/inuse && rm /templates/apple
Or
cp /template...
Gradient of n colors ranging from color 1 and color 2
I often work with ggplot2 that makes gradients nice ( click here for an example ). I have a need to work in base and I think scales can be used there to create color gradients as well but I'm severely off the mark on how. The basic goal is generate a palette of n colors that ranges from x colo...
Maximum and Minimum values for ints
I am looking for minimum and maximum values for integers in python. For eg., in Java, we have Integer.MIN_VALUE and Integer.MAX_VALUE . Is there something like this in python?
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How to automatically crop and center an image
...his version retains the img tag so that we do not lose the ability to drag or right-click to save the image. Credit to Parker Bennett for the opacity trick.
.center-cropped {
width: 100px;
height: 100px;
background-position: center center;
background-repeat: no-repeat;
overflow: ...