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Why does ~True result in -2?
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int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins...
Detect if a page has a vertical scrollbar?
... +1 but for the sake of exactness, this only checks whether the content expands further than the viewport. If the overflow property of the body is set to hidden somewhere along the line, it won't work. Setting hidden on a body is extremely rare, though.
– Pekka
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Why does Java allow us to compile a class with a name different than the file name?
I have a file Test.java and the following code inside it.
8 Answers
8
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What is the runtime performance cost of a Docker container?
I'd like to comprehensively understand the run-time performance cost of a Docker container. I've found references to networking anecdotally being ~100µs slower .
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Task not serializable: java.io.NotSerializableException when calling function outside closure only o
...sk to fail. Now this doesn't mean that you can serialise an RDD with Spark and avoid NotSerializableException
Spark is a distributed computing engine and its main abstraction is a resilient distributed dataset (RDD), which can be viewed as a distributed collection. Basically, RDD's elements are par...
Is it a bad practice to use an if-statement without curly braces? [closed]
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The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways.
Maintainability-wise, it's always smarter to use the second form.
EDIT: ...
Detect a finger swipe through JavaScript on the iPhone and Android
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Simple vanilla JS code sample:
document.addEventListener('touchstart', handleTouchStart, false);
document.addEventListener('touchmove', handleTouchMove, false);
var xDown = null;
var yDown = null;
function getTouches(evt) {
retur...
What is array to pointer decay?
...mbers = 0x5a5aff23. More importantly the term decay signifies loss of type and dimension; numbers decay into int* by losing the dimension information (count 5) and the type is not int [5] any more. Look here for cases where the decay doesn't happen.
If you're passing an array by value, what you're ...
Difference between Activity and FragmentActivity
I was working on fragments and came across two things Activity and FragmentActivity which are used several times. I want to know that is there any difference between these two, because when I changed Activity with FragmentActivity , it had no effect on the app.
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difference between foldLeft and reduceLeft in Scala
I have learned the basic difference between foldLeft and reduceLeft
7 Answers
7
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