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Object reference not set to an instance of an object.Why doesn't .NET show which object is `null`?
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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 ...
getenv() vs. $_ENV in PHP
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answered Nov 15 '16 at 21:41
Leopoldo SanczykLeopoldo Sanczyk
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Is inject the same thing as reduce in ruby?
...ry it takes up.)
– ChrisPhoenix
Oct 15 '14 at 1:39
19
hm, I think the current Ruby docs ruby-doc....
How to intercept touches events on a MKMapView or UIWebView objects?
...lot of hackish programming that imperfectly duplicates Apple's code, especially in the case of multitouch.
Here's what I do: Implement a gesture recognizer that cannot be prevented and that cannot prevent other gesture recognizers. Add it to the map view, and then use the gestureRecognizer's touc...
C# 4.0 optional out/ref arguments
Does C# 4.0 allow optional out or ref arguments?
9 Answers
9
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Can someone explain the traverse function in Haskell?
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traverse is the same as fmap, except that it also allows you to run effects while you're rebuilding the data structure.
Take a look at the example from the Data.Traversable documentation.
data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
The Functor instance of Tr...
Is it possible to GROUP BY multiple columns using MySQL?
...garding SUM using with GROUP BY. If GROUP BY only by one column, then SUMs all values of each distinct (different) the column value sqlfiddle.com/#!9/1cbde2/2. If GROUP BY two columns. Then mysql at first checks if for the first column value there are different values in the second column. If yes, t...
Can I have an IF block in DOS batch file?
...t, and the opening parenthesis.
I am setting @echo off to keep from seeing all of the statements printed to the console as they execute, and instead just see the output of those that specifically begin with echo.
I'm using the built-in ERRORLEVEL variable just as a test. Read more here
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Android Use Done button on Keyboard to click button
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You can use this one also (sets a special listener to be called when an action is performed on the EditText), it works both for DONE and RETURN:
max.setOnEditorActionListener(new OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int acti...
Regex Named Groups in Java
... Brian ClozelBrian Clozel
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