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“Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP
... can be used to detect if a variable has been already initialized. Additionally and more ideal is the solution of empty() since it does not generate a warning or error message if the variable is not initialized.
From PHP documentation:
No warning is generated if the variable does not exist. T...
How to make Twitter Bootstrap tooltips have multiple lines?
...TSZSL/53/
Neither of these will work with a \n in the html, they must actually be actual newlines. Alternatively, you can use encoded newlines &#013;, but that's probably even less desirable than using <br>'s.
sha...
What does the line “#!/bin/sh” mean in a UNIX shell script?
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It's called a shebang, and tells the parent shell which interpreter should be used to execute the script.
e.g.
#!/usr/bin/perl <--perl script'
#!/usr/bin/php <-- php script
#!/bin/false <--- do-nothing script, because ...
What to add for the update portion in ConcurrentDictionary AddOrUpdate
...d] = sessionId;
Store a key/value pair into the dictionary unconditionally, overwriting any value for that key if the key already exists: Use the indexer’s setter
(See: http://blogs.msdn.com/b/pfxteam/archive/2010/01/08/9945809.aspx)
The indexer is atomic, too. If you pass a function inst...
Pass parameter to fabric task
How can I pass a parameter to a fabric task when calling "fab" from the command line? For example:
5 Answers
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Saving grid.arrange() plot to file
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ggsave is not working with (some or all) grobs anymore.
– vak
Oct 29 '15 at 14:50
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How can I perform a str_replace in JavaScript, replacing text in JavaScript?
...erf, you can have different levels of efficiency for creating a regex, but all of them are significantly slower than a simple string replace. The regex is slower because:
Fixed-string matches don't have backtracking, compilation steps, ranges, character classes, or a host of other features that ...
How to un-escape a backslash-escaped string?
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Basically for Python3 you want print(b"Hello,\nworld!".decode('unicode_escape'))
– ChristopheD
Apr 7 '15 at 8:35
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How to use support FileProvider for sharing content to other apps?
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Using FileProvider from support library you have to manually grant and revoke permissions(at runtime) for other apps to read specific Uri. Use Context.grantUriPermission and Context.revokeUriPermission methods.
For example:
//grant permision for app with package "packegeName", ...
How to use Chrome's network debugger with redirects
The Chrome network debugger gives me a great view of all the HTTP resources loaded for a page. But it clears the list whenever a new top-level HTML page is loaded. This makes it very difficult to debug pages that automatically reload for one reason or another (running script or 300 responses).
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