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How to check if a variable is set in Bash?
...ar+x} is a parameter expansion which evaluates to nothing if var is unset, and substitutes the string x otherwise.
Quotes Digression
Quotes can be omitted (so we can say ${var+x} instead of "${var+x}") because this syntax & usage guarantees this will only expand to something that does not requ...
Remove last item from array
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@PrithvirajMitra You want to remove 1 and 0? So the array ==[2] ?
– Anton
Oct 23 '13 at 14:40
3
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How to check whether an object has certain method/property?
...ethod(methodName) != null;
}
Edit : you can even do an extension method and use it like this
myObject.HasMethod("SomeMethod");
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What is the difference between Int and Integer?
In Haskell, what is the difference between an Int and an Integer ? Where is the answer documented?
6 Answers
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What is an 'endpoint' in Flask?
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How Flask Routing Works
The entire idea of Flask (and the underlying Werkzeug library) is to map URL paths to some logic that you will run (typically, the "view function"). Your basic view is defined like this:
@app.route('/greeting/<name>')
def give_greeting(name):
...
Check if an element is a child of a parent
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If you are only interested in the direct parent, and not other ancestors, you can just use parent(), and give it the selector, as in target.parent('div#hello').
Example: http://jsfiddle.net/6BX9n/
function fun(evt) {
var target = $(evt.target);
if (target.pare...
How to make graphics with transparent background in R using ggplot2?
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Updated with the theme() function, ggsave() and the code for the legend background:
df <- data.frame(y = d, x = 1, group = rep(c("gr1", "gr2"), 50))
p <- ggplot(df) +
stat_boxplot(aes(x = x, y = y, color = group),
fill = "transparent" # for the...
Setting the MySQL root user password on OS X
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Try the command FLUSH PRIVILEGES when you log into the MySQL terminal. If that doesn't work, try the following set of commands while in the MySQL terminal
$ mysql -u root
mysql> USE mysql;
mysql> UPDATE user SET password=PASSWORD...
How to check if a specified key exists in a given S3 bucket using Java
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Use the jets3t library. Its a lot more easier and robust than the AWS sdk. Using this library you can call, s3service.getObjectDetails(). This will check and retrieve only the details of the object (not the contents) of the object. It will throw a 404 if the object is mi...
Hide scroll bar, but while still being able to scroll
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Since the scrollbar width differs in different browsers, it is better to handle it with JavaScript. If you do Element.offsetWidth - Element.clientWidth, the exact scrollbar width will show up.
JavaScript Working Fiddle
Or
Using Position: absolute,
#parent{
width: 100%;
height: 100%;
ove...