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When does invoking a member function on a null instance result in undefined behavior?
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Both (a) and (b) result in undefined behavior. It's always undefined behavior to call a member function through a null pointer. If the function is static, it's technically undefined as well, but there's some dispute.
The first thin...
How to check a checkbox in capybara?
I'm using Rspec and Capybara.
13 Answers
13
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PHP: If internet explorer 6, 7, 8 , or 9
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This is what I ended up using a variation of, which checks for IE8 and below:
if (preg_match('/MSIE\s(?P<v>\d+)/i', @$_SERVER['HTTP_USER_AGENT'], $B) && $B['v'] <= 8) {
// Browsers IE 8 and below
} else {
// All other browsers
}
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Setting property 'source' to 'org.eclipse.jst.jee.server:JSFTut' did not find a matching property
...xt> element in Tomcat's server.xml contains an unknown attribute source and that Tomcat doesn't know what to do with this attribute and therefore will ignore it.
Eclipse WTP adds a custom attribute source to the project related <Context> element in the server.xml of Tomcat which identifies...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...re allowed (e.g. changing order of elements of each vector, changing order and names of variables, shortening variables, changing case of strings). From this, you should be able to figure out what was missing from one or the other. For example (this is not very elegant):
difference <-
data.fr...
What are some compelling use cases for dependent method types?
...perimental feature before, has now been enabled by default in the trunk , and apparently this seems to have created some excitement in the Scala community.
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Get names of all files from a folder with Ruby
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You also have the shortcut option of
Dir["/path/to/search/*"]
and if you want to find all Ruby files in any folder or sub-folder:
Dir["/path/to/search/**/*.rb"]
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C# - Keyword usage virtual+override vs. new
What are differences between declaring a method in a base type " virtual " and then overriding it in a child type using the " override " keyword as opposed to simply using the " new " keyword when declaring the matching method in the child type?
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How to stop EditText from gaining focus at Activity startup in Android
I have an Activity in Android, with two elements:
52 Answers
52
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How to get an object's properties in JavaScript / jQuery?
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You can look up an object's keys and values by either invoking JavaScript's native for in loop:
var obj = {
foo: 'bar',
base: 'ball'
};
for(var key in obj) {
alert('key: ' + key + '\n' + 'value: ' + obj[key]);
}
or using jQuery's .each()...