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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...
How to reuse an ostringstream?
...lear, then seek the appropriate sequence to the begin:
s.clear();
s.seekp(0); // for outputs: seek put ptr to start
s.seekg(0); // for inputs: seek get ptr to start
That will prevent some reallocations done by str by overwriting whatever is in the output buffer currently instead. Results are like...
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 ...
How to wait in bash for several subprocesses to finish and return exit code !=0 when any subprocess
...ral subprocesses spawned from that script to finish and return exit code !=0 when any of the subprocesses ends with code !=0 ?
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Check if an array is empty or exists
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if (typeof image_array !== 'undefined' && image_array.length > 0) {
// the array is defined and has at least one element
}
Your problem may be happening due to a mix of implicit global variables and variable hoisting. Make sure you use var whenever declaring a variable:
<?php e...
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...
Regex to validate password strength
...itive look ahead assertions:
^(?=.*[A-Z].*[A-Z])(?=.*[!@#$&*])(?=.*[0-9].*[0-9])(?=.*[a-z].*[a-z].*[a-z]).{8}$
Rubular link
Explanation:
^ Start anchor
(?=.*[A-Z].*[A-Z]) Ensure string has two uppercase letters.
(?=.*[!@#$&*]) Ensure string ha...
Accessing localhost:port from Android emulator
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420
You can access your host machine with the IP address "10.0.2.2".
This has been designed in thi...
When should Flask.g be used?
...w that g will move from the request context to the app context in Flask 0.10, which made me confused about the intended use of g .
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Python assigning multiple variables to same value? list behavior
...y the behavior, I expect to reassign the values list separately, I mean b[0] and c[0] equal 0 as before.
9 Answers
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