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Abort makefile if variable not set
... an auxiliary function for that:
# Check that given variables are set and all have non-empty values,
# die with an error otherwise.
#
# Params:
# 1. Variable name(s) to test.
# 2. (optional) Error message to print.
check_defined = \
$(strip $(foreach 1,$1, \
$(call __check_defined,$...
How can I programmatically check whether a keyboard is present in iOS app?
... responder. I have a view controller with multiple child view controllers, all of which contain UITextFields. Using this method, i cannot tell from my parent view controller whether the keyboard is shown. The only reliable way is to use the notification method explained in the other answers
...
Circular list iterator in Python
...
Output:
a b c a b c ...
(Loops forever, obviously)
In order to manually advance the iterator and pull values from it one by one, simply call next(pool):
>>> next(pool)
'a'
>>> next(pool)
'b'
share...
Difference between Node object and Element object?
I am totally confused between Node object and Element object.
document.getElementById() returns Element object while document.getElementsByClassName()
returns NodeList object(Collection of Elements or Nodes?)
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C# Sanitize File Name
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And another potentially great SO user goes walking... This function is great. Thank you Adrevdm...
– Dan Rosenstark
Aug 1 '09 at 2:15
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Convert a row of a data frame to vector
...
Might have been changed in the meantime, but today unlist allows dropping names: identical(unlist(df[1,], use.names = FALSE), as.numeric(df[1,])) (and btw df still is not a sensible name for a data.frame... ;-))
– Andri Signorell
Sep 25 '1...
Bring element to front using CSS
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I don't really remember the circumstances of my question clearly, but my problem was, that I understood what z-index does, but still it did not work. What I have learned from this answer is, that with z-index you have to take into cons...
Flex-box: Align last row to grid
...d:after and it works the same. Now if you tried something like this it totally breaks. Notice the widths for each set of 4 dont add up to 100%. In the OP's fiddle the widths are set in px so your solution doesn't work this situation.
– Jacob
Jan 26 '16 at 15...
How to verify if a file exists in a batch file?
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Reminder: IF, EXIST, ELSE, REM, DEL, etc. all work in lowercase as well!
– Terra Ashley
Jul 19 '16 at 23:57
1
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Is bool a native C type?
... in the current C - C99, but not in C89/90.
In C99 the native type is actually called _Bool, while bool is a standard library macro defined in stdbool.h (which expectedly resolves to _Bool). Objects of type _Bool hold either 0 or 1, while true and false are also macros from stdbool.h.
Note, BTW, t...