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When would you use a WeakHashMap or a WeakReference?
...When have you needed to use a WeakHashMap or WeakReference and how was it used?
10 Answers
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How to kill an Android activity when leaving it so that it cannot be accessed from the back button?
In an given Android activity, I would like to start a new activity for the user at some point. Once they leave the first activity and arrive at the second, the first activity is stale and I want to remove it completely so it can not be accessed again from the back button.
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c# open a new form then close the current form?
...es not work. When calling this.Close(), current form is disposed together with form2. Therefore you need to hide it and set form2.Closed event to call this.Close().
private void OnButton1Click(object sender, EventArgs e)
{
this.Hide();
var form2 = new Form2();
form2.Closed += (s, args) ...
Why doesn't Java support unsigned ints?
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This is from an interview with Gosling and others, about simplicity:
Gosling: For me as a language designer, which I don't really count myself as these days, what "simple" really ended up meaning was could I expect J. Random Developer to hold the s...
gdb fails with “Unable to find Mach task port for process-id” error
My app runs fine but gdb fails to debug it with the following error
12 Answers
12
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Why are side-effects modeled as monads in Haskell?
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Suppose a function has side effects. If we take all the effects it produces as the input and output parameters, then the function is pure to the outside world.
So, for an impure function
f' :: Int -> Int
we add the RealWorld to the consideration
f :: Int -> RealWorld -> (Int, Re...
width:auto for fields
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An <input>'s width is generated from its size attribute. The default size is what's driving the auto width.
You could try width:100% as illustrated in my example below.
Doesn't fill width:
<form action='' method='post' style='width:200px;background:khaki'...
Add all files to a commit except a single file?
...ant to specifically ignore a single modified file. Looks like this after git status :
13 Answers
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Start a git commit message with a hashmark (#)
Git treats lines starting with # as comment lines when committing. this is very annoying when working with a ticket tracking system, and trying to write the ticket number at the beginning of the line, e.g.
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Laravel Check If Related Model Exists
...In php 7.2+ you can't use count on the relation object, so there's no one-fits-all method for all relations. Use query method instead as @tremby provided below:
$model->relation()->exists()
generic solution working on all the relation types (pre php 7.2):
if (count($model->relation))
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