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How do I handle too long index names in a Ruby on Rails ActiveRecord migration?
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Provide the :name option to add_index, e.g.:
add_index :studies,
["user_id", "university_id", "subject_name_id", "subject_type_id"],
:unique => true,
:name => 'my_index'
If using the :index option on references in a create_table block, it t...
Is VB really case insensitive?
...m not trying to start an argument here, but for whatever reason, it's typically stated that Visual Basic is case insensitive and C languages aren't (and somehow that is a good thing).
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What are the benefits of functional programming? [closed]
...bel refers to a version of this array where this function has been done on all the elements."
Functional programming moves more basic programming ideas into the compiler, ideas such as list comprehensions and caching.
The biggest benefit of Functional programming is brevity, because code can be mo...
What does Java option -Xmx stand for? [duplicate]
...it says,
-Xmxn
Specify the maximum size, in bytes, of the memory allocation pool. This value must a multiple of 1024 greater than 2MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 64MB. The upper limit for this value will be approxim...
Making a Simple Ajax call to controller in asp.net mvc
...er, it's Url.Action(actionName, controllerName)
– xd6_
Apr 27 '17 at 22:20
1
Not a fan of this, i...
When should null values of Boolean be used?
Java boolean allows values of true and false while Boolean allows true , false , and null . I have started to convert my boolean s to Boolean s. This can cause crashes in tests such as
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Adding an onclick function to go to url in JavaScript?
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@FayazMd not sure what you're trying to do? Usually if it's JavaScript inside the DOM (currenty inside DOM's element a) as a web page you can not control JS behaviour on the next page (where you're redirecting the browser page). When user leaves the page it's done. Unle...
Switching to a TabBar tab view programmatically?
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Like Stuart Clark's solution but for Swift 3:
func setTab<T>(_ myClass: T.Type) {
var i: Int = 0
if let controllers = self.tabBarController?.viewControllers {
for controller in controllers {
if let nav = controller as? UINavigationController, nav.topViewCont...
What does the `forall` keyword in Haskell/GHC do?
I'm beginning to understand how the forall keyword is used in so-called "existential types" like this:
8 Answers
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Can an Android NFC phone act as an NFC tag?
... a simple old nfc tag? Is there some application I'm not thinking of? Usually, you'd want to emulate something like a transit card, access key, or credit card which would require a secure element (I think, but not sure).
s...