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What does an exclamation mark mean in the Swift language?
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"forced unwrapping": john! (gives the Person value if it exists, runtime error if it is nil)
"optional binding": if let p = john { println(p) } (executes the println if the value exists)
"optional chaining": john?.learnAboutSwift() (executes this made-up method if the value exists)
I guess you c...
What is the command to exit a Console application in C#?
... is cleaner because it gives the underlying operating system a more useful error code why it is exiting.
– Fayssal El Mofatiche
Nov 8 '17 at 8:23
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Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant f
...er may have the wrong class in your xib.
I downloaded your project.
The error you are getting is
'NSUnknownKeyException', reason: '[<UIViewController 0x3927310> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key string.'
It is caused by the Second vi...
TypeLoadException says 'no implementation', but it is implemented
I've got a very weird bug on our test machine. The error is:
38 Answers
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Should I use .done() and .fail() for new jQuery AJAX code instead of success and error
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As stated by user2246674, using success and error as parameter of the ajax function is valid.
To be consistent with precedent answer, reading the doc :
Deprecation Notice:
The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callbacks will be deprecated in jQuery ...
E11000 duplicate key error index in mongodb mongoose
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The error message is saying that there's already a record with null as the email. In other words, you already have a user without an email address.
The relevant documentation for this:
If a document does not have a value for the...
HTML: Include, or exclude, optional closing tags?
...spec clearly specifies when it's valid to omit tags, so it's not always an error.
For example you never need </body></html>. Nobody ever remembers to put <tbody> explicitly (to the point that XHTML made exceptions for it).
You don't need </head><body> unless you have ...
How to get JSON from URL in JavaScript?
...ng Node.js? Then take a look over here. But next time try googling for the error first, the link I posted is the first result that comes up when I type the error into Google.
– Robin Hartmann
Jun 11 '18 at 12:41
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Haskell error parse error on input `='
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Starting in GHC 8.0.1 this would no longer generate an error.
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Undefined symbols for architecture i386: _OBJC_CLASS_$_SKPSMTPMessage", referenced from: error
...background i.e. SKPSMTPMessage Framework. Can somebody suggest why below error is shown
35 Answers
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