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What is an “unwrapped value” in Swift?
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cantBeNil = nil // can't do this
To get the value from your variable if it is optional, you have to unwrap it. This just means putting an exclamation point at the end.
var canBeNil : Int? = 4
println(canBeNil!)
Your code should look like this:
let optionalSquare: Square? = Square(sideLength: ...
Difference between string and char[] types in C++
I know a little C and now I'm taking a look at C++.
I'm used to char arrays for dealing with C strings, but while I look at C++ code I see there are examples using both string type and char arrays:
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Remove a symlink to a directory
...ory. I want to get rid of that symlink, while keeping the directory behind it.
9 Answers
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Is it possible to run JavaFX applications on iOS, Android or Windows Phone 8?
Can one develop an entire application using JavaFX and run it on iOS, Android or Windows Phone 8, without writing platform-specific code?
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How do you set, clear, and toggle a single bit?
How do you set, clear, and toggle a bit?
30 Answers
30
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When to use enumerateObjectsUsingBlock vs. for
...o use and comes more naturally in the context.
While for(... in ...) is quite convenient and syntactically brief, enumerateObjectsUsingBlock: has a number of features that may or may not prove interesting:
enumerateObjectsUsingBlock: will be as fast or faster than fast enumeration (for(... in ......
How do I test if a string is empty in Objective-C?
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You can check if [string length] == 0. This will check if it's a valid but empty string (@"") as well as if it's nil, since calling length on nil will also return 0.
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Is it possible to have SSL certificate for IP address, not domain name?
I want my site to use URLs like http://192.0.2.2/... and https://192.0.2.2/... for static content to avoid unnecessary cookies in request AND avoid additional DNS request.
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Why doesn't Java Map extend Collection?
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mappings are not collections and
collections are not mappings. Thus, it
makes little sense for Map to extend
the Collection interface (or vice
versa).
If a Map is a Collection, what are the
elements? The only reasonable answer
is "Key-value pairs", but this
provides a very lim...
Random shuffling of an array
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Using Collections to shuffle an array of primitive types is a bit of an overkill...
It is simple enough to implement the function yourself, using for example the Fisher–Yates shuffle:
import java.util.*;
import java.util.concurrent.ThreadLocalRandom;
class Test
{
...