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php is null or empty?

...===. When use ==, as you did, PHP treats NULL, false, 0, the empty string, and empty arrays as equal. share | improve this answer | follow | ...
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When is an interface with a default method initialized?

....4.1 ought to cover this definitively. However, the behavior of Oracle JDK and OpenJDK (javac and HotSpot) differs from what's specified here. In particular, the Example 12.4.1-3 from this section covers interface initialization. The example as follows: interface I { int i = 1, ii = Test.out("i...
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Iterating over every two elements in a list

...+ y) In Python 3, you can replace izip with the built-in zip() function, and drop the import. All credit to martineau for his answer to my question, I have found this to be very efficient as it only iterates once over the list and does not create any unnecessary lists in the process. N.B: This ...
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Can I replace groups in Java regex?

I have this code, and I want to know, if I can replace only groups (not all pattern) in Java regex. Code: 7 Answers ...
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What ports does RabbitMQ use?

...olution of node names in a cluster. Nodes must be able to reach each other and the port mapper daemon for clustering to work. PORT 35197 set by inet_dist_listen_min/max Firewalls must permit traffic in this range to pass between clustered nodes RabbitMQ Management console: PORT 15672 for RabbitM...
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write a shell script to ssh to a remote machine and execute commands

... There are multiple remote linux machines, and I need to write a shell script which will execute the same set of commands in each machine. (Including some sudo operations). How can this be done using shell scripting? You can do this with ssh, for example: #!/bin/ba...
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How do I link to Google Maps with a particular longitude and latitude?

I have a small application that gives the current location: longitude and latitude. Now I have to browse to google maps with the longitude and latitude. Please suggest how I can do this. ...
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Positioning element at center of screen

...creen irrespective of screen size. In other words, the space left on 'top' and 'bottom' should be equal and space left on 'right' and 'left' sides should be equal. I would like to accomplish this with only CSS. ...
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Mongodb Explain for Aggregation framework

...t, $geonear at the beginning of a pipeline) as well as subsequent $lookup and $graphLookup stages. Once data has been fetched into the aggregation pipeline for processing (e.g. passing through stages like $project, $unwind, and $group) further manipulation will be in-memory (possibly using temporar...
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What is the difference between a var and val definition in Scala?

What is the difference between a var and val definition in Scala and why does the language need both? Why would you choose a val over a var and vice versa? ...