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The differences between .build, .create, and .create! and when should they be used?
So I've been seeing people using .build , .create , and .create! within their controllers more and more lately. What's the difference from just using .new and passing the param'd object and then .save ? Are there pros and cons? Does using these other methods offer benefits?
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Should each and every table have a primary key?
I'm creating a database table and I don't have a logical primary key assigned to it. So, I'm thinking about leaving it without a primary key, but I'm feeling a bit guilty about it. Should I?
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MySQL selecting yesterday's date
How can I display and count the values whose dates are yesterday?
I used time() to insert date in the database. Example:
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Hidden Features of Xcode
...h a huge influx of newbies to Xcode, I'm sure there are lots of Xcode tips and tricks to be shared.
89 Answers
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How do I adjust the anchor point of a CALayer, when Auto Layout is being used?
...at in layoutSubviews the runtime comes dashing through all the constraints and setting the frames of all the views accordingly.
In other words, the constraints are not magic; they are just a to-do list. layoutSubviews is where the to-do list gets done. And it does it by setting frames.
I can't hel...
Multiple arguments vs. options object
...gLength(inputStr, 10);
I think that code is quite readable the way it is and passing individual parameters is just fine.
On the other hand, there are functions with calls like this:
initiateTransferProtocol("http", false, 150, 90, null, true, 18);
Completely unreadable unless you do some resea...
What is the difference between an IntentService and a Service? [duplicate]
Can you please help me understand what the difference between an IntentService and a Service is?
8 Answers
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What is the difference between map and flatMap and a good use case for each?
Can someone explain to me the difference between map and flatMap and what is a good use case for each?
16 Answers
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“static const” vs “#define” vs “enum”
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It depends on what you need the value for. You (and everyone else so far) omitted the third alternative:
static const int var = 5;
#define var 5
enum { var = 5 };
Ignoring issues about the choice of name, then:
If you need to pass a pointer around, you must use (1).
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Why does Java's hashCode() in String use 31 as a multiplier?
...to Joshua Bloch's Effective Java (a book that can't be recommended enough, and which I bought thanks to continual mentions on stackoverflow):
The value 31 was chosen because it is an odd prime. If it were even and the multiplication overflowed, information would be lost, as multiplication by 2 i...