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When to use -retainCount?
...d think that @"Foo" would have a retainCount of 1. It doesn't. It's 1152921504606846975.
You'd think that [NSString stringWithString:@"Foo"] would have a retainCount of 1. It doesn't. Again, it's 1152921504606846975.
Basically, since anything can retain an object (and therefore alter its retai...
Grouped LIMIT in PostgreSQL: show the first N rows for each group?
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ngspkinga
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answered May 19 '11 at 19:55
DaveDave
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How can I output UTF-8 from Perl?
...tant distinction.
– Chas. Owens
Apr 21 '09 at 13:06
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show 3 more comments
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Scala @ operator
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answered Mar 1 '10 at 21:56
Daniel C. SobralDaniel C. Sobral
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Determine the data types of a data frame's columns
...use ?str(). To explore some examples, let's make some data:
set.seed(3221) # this makes the example exactly reproducible
my.data <- data.frame(y=rnorm(5),
x1=c(1:5),
x2=c(TRUE, TRUE, FALSE, FALSE, FALSE),
X3=letters[1:5])
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Filter rows which contain a certain string
...))
mpg cyl disp hp drat wt qsec vs am gear carb type
1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 Mazda RX4
2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 Mazda RX4 Wag
3 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 Toyota Corolla
4 21.5 4 120.1 97...
in_array multiple values
... Mark ElliotMark Elliot
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13
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Print a string as hex bytes?
...nd I want to print it using Python as 48:65:6c:6c:6f:20:77:6f:72:6c:64:20:21:21 .
13 Answers
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How to check status of PostgreSQL server Mac OS X
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answered Sep 2 '13 at 21:55
l3xl3x
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Difference between git pull and git pull --rebase
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answered Sep 21 '13 at 8:28
mvpmvp
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