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What is a NullPointerException, and how do I fix it?
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When you declare a reference variable (i.e. an object) you are really creating a pointer to an object. Consider the following code where you declare a variable of primitive type int:
int x;
x = 10;
In this example, the variable x is an int and Java will initialize it to 0 for you. When yo...
Summarizing multiple columns with dplyr? [duplicate]
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The dplyr package contains summarise_all for this aim:
library(dplyr)
df %>% group_by(grp) %>% summarise_all(list(mean))
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#>...
Passing variable arguments to another function that accepts a variable argument list
...gs)
{
...whatever you planned to have exampleB do...
...except it calls neither va_start nor va_end...
}
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How to download Xcode DMG or XIP file?
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For Xcode 9, I am told that I am not allowed to view that page. What shall I do?
– Mr. Xcoder
Jun 6 '17 at 18:45
9
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Bold & Non-Bold Text In A Single UILabel?
...deal with iOS5 old stuff besides syntax is shorter so everything becomes really simple:
Swift 5
func attributedString(from string: String, nonBoldRange: NSRange?) -> NSAttributedString {
let fontSize = UIFont.systemFontSize
let attrs = [
NSAttributedString.Key.font: UIFont.bold...
Split files using tar, gz, zip, or bzip2 [closed]
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Actually using -b 1024MiB gave an error that it was an invalid number of bytes. Using --bytes=1024m works.
– Brian
Mar 13 '14 at 12:52
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When do I use the PHP constant “PHP_EOL”?
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@Andre: How about anyone that writes apps to be installed, used and deployed by others? Are you suggesting these should all limit their "supported platforms" to *nix?
– Cylindric
Mar 4 '11 at 10:52
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What's the state of the art in email validation for Rails?
... answered Aug 24 '10 at 9:56
HallelujahHallelujah
77466 silver badges44 bronze badges
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How can I start an interactive console for Perl?
...ms to provide the best almost-out-of-the-box solution (you may have to install rlwrap). All third-party REPL/console solutions, including perlconsole, are cumbersome to install and often have more limitations.
– mklement0
Jul 8 '15 at 3:09
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How do I get current date/time on the Windows command line in a suitable format for usage in a file/
Update: Now that it's 2016 I'd use PowerShell for this unless there's a really compelling backwards-compatible reason for it, particularly because of the regional settings issue with using date . See @npocmaka's https://stackoverflow.com/a/19799236/8479
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