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Swift: Testing optionals for nil
... // Do something using `xyz`.
}
This produces an error:
does not conform to protocol 'BooleanType.Protocol'
You have to use one of these forms:
if xyz != nil {
// Do something using `xyz`.
}
if let xy = xyz {
// Do something using `xy`.
}
...
@RequestParam vs @PathVariable
... edited Apr 14 at 9:27
informatik01
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answered Nov 28 '19 at 11:59
...
Is “else if” a single keyword?
...he substatement in a selection-statement (each substatement, in the
else form of the if statement) implicitly defines a block scope (3.3).
If the substatement in a selection-statement is a single statement and
not a compound-statement, it is as if it was rewritten to be a
compound-statement ...
What's the syntax for mod in java
...l add a bit of additional context. % the "modulus" operator is actually performing the remainder operation. The difference between mod and rem is subtle, but important.
(-1 mod 2) would normally give 1. More specifically given two integers, X and Y, the operation (X mod Y) tends to return a value...
Why doesn't adding CORS headers to an OPTIONS route allow browsers to access my API?
...TIONS call) are any Content-Type except the following:
application/x-www-form-urlencoded
multipart/form-data
text/plain
Any other Content-Types apart from those listed above will trigger a pre-flight request.
As for Headers, any Request Headers apart from the following will trigger a pre-flight...
How to check if a string in Python is in ASCII?
...o the try/except. Here the loop is in the interpreter. With the try/except form, the loop is in the C codec implementation called by str.decode('ascii'). And I agree, the try/except form is more pythonic too.
– ddaa
Oct 16 '08 at 17:55
...
How do I exit a WPF application programmatically?
In the few years I've been using C# (Windows Forms), I've never used WPF. But, now I love WPF, but I don't know how I am supposed to exit my application when the user clicks on the Exit menu item from the File menu.
...
How to convert Milliseconds to “X mins, x seconds” in Java?
... variable, and I want to show them the time elapsed using a human readable format such as "XX hours, XX mins, XX seconds" or even "XX mins, XX seconds" because its not likely to take someone an hour.
...
Quick and easy file dialog in Python?
...TA mode
co_initialize(None)
import clr
clr.AddReference('System.Windows.Forms')
from System.Windows.Forms import OpenFileDialog
file_dialog = OpenFileDialog()
ret = file_dialog.ShowDialog()
if ret != 1:
print("Cancelled")
sys.exit()
print(file_dialog.FileName)
If you also miss more c...
Why use the 'ref' keyword when passing an object?
... reference types (e.g. List<T>) as holding object identifiers of the form "Object #24601". Suppose the statement foo = new List<int> {1,5,7,9}; causes foo to hold "Object #24601" (a list with four items). Then calling foo.Length will ask Object #24601 for its length, and it will respon...