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In Objective-C why should I check if self = [super init] is not nil?
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For example:
[[NSData alloc] initWithContentsOfFile:@"this/path/doesn't/exist/"];
[[NSImage alloc] initWithContentsOfFile:@"unsupportedFormat.sjt"];
[NSImage imageNamed:@"AnImageThatIsntInTheImageCache"];
... and so on. (Note: NSData might throw...
What is the difference between std::array and std::vector? When do you use one over other? [duplicat
...ssic C array. That means its size is fixed at compile time and it will be allocated as a single chunk (e.g. taking space on the stack). The advantage it has is slightly better performance because there is no indirection between the object and the arrayed data.
std::vector is a small class contain...
Creating an array of objects in Java
...is:
A a1;
A a2;
A a3;
A a4;
Now you couldn't do a1.someMethod() without allocating a1 like this:
a1 = new A();
Similarly, with the array you need to do this:
a[0] = new A();
...before using it.
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What exactly does an #if 0 … #endif block do?
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When the preprocessor sees #if it checks whether the next token has a non-zero value. If it does, it keeps the code around for the compiler. If it doesn't, it gets rid of that code so the compiler never sees it.
If someone says #if 0 they are effectively commenting out the code s...
How to generate a random string of a fixed length in Go?
...n terms of speed, and it will definitely help in terms of memory usage and allocations.
func RandStringBytesMaskImprSrcSB(n int) string {
sb := strings.Builder{}
sb.Grow(n)
// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
for i, cache, remain := n-1, sr...
How to embed small icon in UILabel
...tKit. Some sample code:
NSTextAttachment *attachment = [[NSTextAttachment alloc] init];
attachment.image = [UIImage imageNamed:@"MyIcon.png"];
NSAttributedString *attachmentString = [NSAttributedString attributedStringWithAttachment:attachment];
NSMutableAttributedString *myString= [[NSMutableAtt...
What is a .snk for?
...lobal Assembly Cache (GAC).
The .snk file contains the public and private tokens for your key. When you want to sign some data (or binary) with that key, a checksum is calculated on the data, which is then encrypted with the private token. The encrypted checksum is then added to the data. Anyone ca...
converting Java bitmap to byte array
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This approach is really wastefull of allocations. Your ByteArrayOutputStream will allocate a byte[] of size equal to the byte[] backing your Bitmap, then ByteArrayOutputStream.toByteArray() will again allocate yet another byte[] of the same size.
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Dismiss keyboard by touching background of UITableView
...hod:
UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)];
[self.tableView addGestureRecognizer:gestureRecognizer];
And the hideKeyboard method might look like this:
- (void) hideKeyboard {
[textField1 resignFirstResp...
Differences between C++ string == and compare()?
...or==
21.4.8.2 operator==
template<class charT, class traits, class Allocator>
bool operator==(const basic_string<charT,traits,Allocator>& lhs,
const basic_string<charT,traits,Allocator>& rhs) noexcept;
Returns: lhs.compare(rhs) == 0.
Seems like ...