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The cast to value type 'Int32' failed because the materialized value is null
...where there can be unexpected nulls in different places. ...DefaultIfEmpty(0).Sum(0) can help in this (quite simple) case, where there might be no elements and sql's SUM returns null whereas c# expect 0.
A more general approach is to use ?? which will be translated to COALESCE whenever there is a r...
Test if a command outputs an empty string
...r success, non-zero for failure). For example:
files=$(ls -A)
if [[ $? != 0 ]]; then
echo "Command failed."
elif [[ $files ]]; then
echo "Files found."
else
echo "No files found."
fi
More info here.
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Best way to find if an item is in a JavaScript array? [duplicate]
...
As of ECMAScript 2016 you can use includes()
arr.includes(obj);
If you want to support IE or other older browsers:
function include(arr,obj) {
return (arr.indexOf(obj) != -1);
}
EDIT:
This will not work on IE6, 7 or 8 though. The be...
Find element's index in pandas Series
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10 Answers
10
Active
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Multiple queries executed in java in single statement
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140
I was wondering if it is possible to execute something like this using JDBC.
"SELECT FROM * TAB...
Does Java support default parameter values?
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answered Jun 15 '09 at 18:14
Kathy Van StoneKathy Van Stone
22.3k22 gold badges2929 silver badges3939 bronze badges
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Difference in System. exit(0) , System.exit(-1), System.exit(1 ) in Java
...seful to know if something went wrong and what went wrong.
Exit code is
0 when execution went fine;
1, -1, whatever != 0 when some error occurred, you can use different values for different kind of errors.
If I'm correct exit codes used to be just positive numbers (I mean in UNIX) and according...
Declare slice or make slice?
In Go, what is the difference between var s []int and s := make([]int, 0) ?
4 Answers
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Determine a string's encoding in C#
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answered Feb 6 '10 at 17:31
devdimidevdimi
2,3561818 silver badges1717 bronze badges
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