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Object reference not set to an instance of an object.Why doesn't .NET show which object is `null`?
...ull
IL_0002: stloc.0 // s
IL_0003: ldloc.0 // s
IL_0004: callvirt System.String.get_Length
IL_0009: call System.Console.WriteLine
It is the callvirt opcode that throws the NullReferenceException and it does that when the first argument on the evaluation stack is a null ...
Is there a recommended format for multi-line imports?
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Personally I go with parentheses when importing more than one component and sort them alphabetically. Like so:
from Tkinter import (
Button,
Canvas,
DISABLED,
END,
Entry,
Frame,
LEFT,
NORMAL,
RI...
How to use phpexcel to read data and insert into database?
...el_Cell::columnIndexFromString($sheet->getHighestColumn()); I am not infallible `
– Mark Baker
Jun 16 '13 at 21:48
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Why is it impossible to override a getter-only property and add a setter? [closed]
Why is the following C# code not allowed:
16 Answers
16
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Define make variable at rule execution time
...r are evaluated. In order to create the directory only when out.tar is actually fired, you need to move the directory creation down into the steps:
out.tar :
$(eval TMP := $(shell mktemp -d))
@echo hi $(TMP)/hi.txt
tar -C $(TMP) cf $@ .
rm -rf $(TMP)
The eval function evaluates a...
Is there a Python equivalent of the C# null-coalescing operator?
In C# there's a null-coalescing operator (written as ?? ) that allows for easy (short) null checking during assignment:
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Is it possible to use getters/setters in interface definition?
At the moment, TypeScript does not allow use get/set methods(accessors) in interfaces.
For example:
4 Answers
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Rails: confused about syntax for passing locals to partials
...:partial => 'foo', :locals => {blah blah blah}) then it will pass in all of your arguments as a hash and parse them accordingly.
If you pass in a string as your first argument, it assumes the first argument is your partial name, and will pass the remainder as your locals. However, in that s...
Package objects
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Normally you would put your package object in a separate file called package.scala in the package that it corresponds to. You can also use the nested package syntax but that is quite unusual.
The main use case for package object...
std::string formatting like sprintf
...mixed cout and printfs are output correctly. Disabling this link (with a call to cout.sync_with_stdio(false)) causes c++'s streams to outperform stdio, at least as of MSVC10.
– Jimbo
Jan 20 '13 at 21:15
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