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What is a NullPointerException, and how do I fix it?

... the object you get a NullPointerException. In the most trivial cases, the compiler will catch the problem and let you know that "num may not have been initialized," but sometimes you may write code that does not directly create the object. For instance, you may have a method as follows: public void...
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What is the difference between “INNER JOIN” and “OUTER JOIN”?

... Assuming you're joining on columns with no duplicates, which is a very common case: An inner join of A and B gives the result of A intersect B, i.e. the inner part of a Venn diagram intersection. An outer join of A and B gives the results of A union B, i.e. the outer parts of a Venn diagram un...
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PHP - concatenate or directly insert variables in string

...cations, those won't matter 1. As a sidenote, so my answer is a bit more complete: the day you'll want to do something like this: echo "Welcome $names!"; PHP will interpret your code as if you were trying to use the $names variable -- which doesn't exist. - note that it will only work if you us...
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Can I change the fill color of an svg path with CSS?

...vg fill="#3F6078" height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> </svg> Use your favorite text editor, open the SVG file and play around with it. ...
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Best way to iterate through a Perl array

...be used? If so, sounds like one shouldn't use that approach. stackoverflow.com/questions/6440723/… rt.cpan.org/Public/Bug/Display.html?id=115863 – Thorsten Schöning Jan 14 '19 at 11:40 ...
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Change URL and redirect using jQuery

...t two slashes after http: on line 2 of your JavaScript: url = "http://abc.com/" + temp; share | improve this answer | follow | ...
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What is Virtual DOM?

...ouching the real DOM or going through the DOM API. Then, when it renders a component, it uses this virtual DOM to figure out what it needs to do with the real DOM to get the two trees to match. You can think of the virtual DOM like a blueprint. It contains all the details needed to construct the DO...
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How to tell PowerShell to wait for each command to end before starting the next?

... Normally, for internal commands PowerShell does wait before starting the next command. One exception to this rule is external Windows subsystem based EXE. The first trick is to pipeline to Out-Null like so: Notepad.exe | Out-Null PowerShell wi...
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Print a file's last modified date in Bash

... You can use the stat command stat -c %y "$entry" More info %y time of last modification, human-readable share | improve this answer ...
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How to include view/partial specific styling in AngularJS

...a ton of research on various solutions to this problem, I think I may have come up with a better solution. UPDATE 1: Since posting this answer, I have added all of this code to a simple service that I have posted to GitHub. The repo is located here. Feel free to check it out for more info. UPDATE...