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Is there any boolean type in Oracle databases?
...read on asktom. From recommending CHAR(1) 'Y'/'N' they switch to NUMBER(1) 0/1 when someone points out that 'Y'/'N' depends on the English language, while e.g. German programmers might use 'J'/'N' instead.
The worst thing is that they defend this stupid decision just like they defend the ''=NULL st...
How to quit scala 2.11.0 REPL?
In the last version of scala (2.10.3) REPL, I can type exit to quit from REPL. However, in Scala 2.11.0 this doesn't work.
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How to get execution time in rails console?
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edited Jul 20 '19 at 4:28
Jeremy Baker
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Relative frequencies / proportions with dplyr
...n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That makes ...
Controlling maven final name of jar artifact
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303
You set the finalName property in the plugin configuration section:
<plugin>
<gro...
How can I count the number of matches for a regex?
... following. (Starting from Java 9, there is a nicer solution)
int count = 0;
while (matcher.find())
count++;
Btw, matcher.groupCount() is something completely different.
Complete example:
import java.util.regex.*;
class Test {
public static void main(String[] args) {
String hel...
Is there XNOR (Logical biconditional) operator in C#?
...te also that this doesn't generalize to bitwise operations, where you want 0x1234 XNOR 0x5678 == 0xFFFFBBB3 (assuming 32 bits). For that, you need to build up from other operations, like ~(A^B). (Note: ~, not !.)
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What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?
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300
Your first port of call should be the documentation which explains it reasonably clearly:
T...
Python using enumerate inside list comprehension
...list)]
Either way, the result that gets returned is as expected:
> [(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')]
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Convert string with commas to array
... JSON.parse("[" + string + "]");
This gives you an Array of numbers.
[0, 1]
If you use .split(), you'll end up with an Array of strings.
["0", "1"]
Just be aware that JSON.parse will limit you to the supported data types. If you need values like undefined or functions, you'd need to use ...