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Getting the first character of a string with $str[0]
...ey send you, from type to type[] for example, and then send 'Control' and 'Test' as the data for this array, $_POST['type'][0] will now return Control rather than C whereas substr($_POST['type'], 0, 1) will simply just fail.
So yes, there may be a problem with using $str[0], but that depends on the...
correct way to define class variables in Python [duplicate]
...e explains the difference between the styles:
james@bodacious-wired:~$cat test.py
#!/usr/bin/env python
class MyClass:
element1 = "Hello"
def __init__(self):
self.element2 = "World"
obj = MyClass()
print dir(MyClass)
print "--"
print dir(obj)
print "--"
print obj.element1
prin...
How to properly reuse connection to Mongodb across NodeJs application and modules
...useNewUrlParser: true }, function( err, client ) {
_db = client.db('test_db');
return callback( err );
} );
},
getDb: function() {
return _db;
}
};
To use it, you would do this in your app.js:
var mongoUtil = require( 'mongoUtil' );
mongoUtil.connectToServer( function...
What is an undefined reference/unresolved external symbol error and how do I fix it?
...urned 1 exit status
and similar errors with Microsoft Visual Studio:
1>test2.obj : error LNK2001: unresolved external symbol "void __cdecl foo(void)" (?foo@@YAXXZ)
1>test2.obj : error LNK2001: unresolved external symbol "int x" (?x@@3HA)
1>test2.obj : error LNK2001: unresolved external sym...
Performance difference for control structures 'for' and 'foreach' in C#
...L_002f: endfinally
} // end handler
IL_0030: ret
} // end of method Test::IterateOverList
The compiler treats arrays differently, converting a foreach loop basically to a for loop, but not List<T>. Here's the equivalent code for an array:
static void IterateOverArray(object[] array)
...
RegEx for Javascript to allow only alphanumeric
...If you wanted to return a replaced result, then this would work:
var a = 'Test123*** TEST';
var b = a.replace(/[^a-z0-9]/gi,'');
console.log(b);
This would return:
Test123TEST
Note that the gi is necessary because it means global (not just on the first match), and case-insensitive, which is wh...
How to verify if a file exists in a batch file?
...ace. After deleting the folder, it will restore those three files.
xcopy "test" "C:\temp"
xcopy "test2" "C:\temp"
del C:\myprogram\sync\
xcopy "C:\temp" "test"
xcopy "C:\temp" "test2"
del "c:\temp"
Use the XCOPY command:
xcopy "C:\myprogram\html\data.sql" /c /d /h /e /i /y "C:\myprogram\sync\"...
mongo group query how to keep fields
...e first matching entries for each group, you can try aggregating like:
db.test.aggregate({
$group: {
_id : '$name',
name : { $first: '$name' },
age : { $first: '$age' },
sex : { $first: '$sex' },
province : { $first: '$province' },
city : { $first: '$city' },
area : { $first:...
Parse a .py file, read the AST, modify it, then write back the modified source code
...
Pythoscope does this to the test cases it automatically generates as does the 2to3 tool for python 2.6 (it converts python 2.x source into python 3.x source).
Both these tools uses the lib2to3 library which is a implementation of the python parser/com...
'printf' vs. 'cout' in C++
... You say I/O is the bottleneck anyway. Obviously you never tested that assumption. I quote myself: "On the other hand, the iostreams version, at 75.3 MB/s, can't buffer data fast enough to keep up with a hard disk. That's bad, and it's not even doing any real work yet. I don't think...