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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 [[ $files ]]; then
echo "Files found."
else
echo "No files found."
fi
More info here.
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Does Java support default parameter values?
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answered Jun 15 '09 at 18:14
Kathy Van StoneKathy Van Stone
22.3k22 gold badges2929 silver badges3939 bronze badges
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Best way to find if an item is in a JavaScript array? [duplicate]
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As of ECMAScript 2016 you can use includes()
arr.includes(obj);
If you want to support IE or other older browsers:
function include(arr,obj) {
return (arr.indexOf(obj) != -1);
}
EDIT:
This will not work on IE6, 7 or 8 though. The be...
Find element's index in pandas Series
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10 Answers
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The cast to value type 'Int32' failed because the materialized value is null
...where there can be unexpected nulls in different places. ...DefaultIfEmpty(0).Sum(0) can help in this (quite simple) case, where there might be no elements and sql's SUM returns null whereas c# expect 0.
A more general approach is to use ?? which will be translated to COALESCE whenever there is a r...
Android Hello-World compile error: Intellij cannot find aapt
...set up with an Android development environment using IntelliJ in Ubuntu 12.04. I create an Android Application Module, but when I try to build, I get the following error:
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Determine a string's encoding in C#
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answered Feb 6 '10 at 17:31
devdimidevdimi
2,3561818 silver badges1717 bronze badges
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PHP: Count a stdClass object
...urn the right number when I run the count($obj) function. The object has 30 properties, but the return on the count() function is say 1.
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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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