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How do I declare a 2d array in C++ using new?
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Remember that anything allocated with new is created on the heap and must be de-allocated with delete, just keep this in mind and be sure to delete this memory from the heap when you're done with it to prevent leaks.
– Kekoa
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Best practices for Storyboard login screen, handling clearing of data upon logout
...oller"];
UINavigationController* navigation = [[UINavigationController alloc] initWithRootViewController:rootController];
self.window.rootViewController = navigation;
}
In SignUpViewController.m file
- (IBAction)actionSignup:(id)sender
{
AppDelegate *appDelegateTemp = [[UIApplication...
How does free know how much to free?
... pointer you like as an argument to free, how does it know the size of the allocated memory to free? Whenever I pass a pointer to some function, I have to also pass the size (ie an array of 10 elements needs to receive 10 as a parameter to know the size of the array), but I do not have to pass the s...
How to efficiently concatenate strings in go
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If you know the total length of the string that you're going to preallocate then the most efficient way to concatenate strings may be using the builtin function copy. If you don't know the total length before hand, do not use copy, and read the other answers instead.
In my tests, that approa...
How can I scan barcodes on iOS?
...tWithDevice:self.device error:nil];
self.session = [[AVCaptureSession alloc] init];
self.output = [[AVCaptureMetadataOutput alloc] init];
[self.session addOutput:self.output];
[self.session addInput:self.input];
[self.output setMetadataObjectsDelegate:self queue:dispatch_get_m...
Coding Practices which enable the compiler/optimizer to make a faster program
...if you care about performance. For example two-dimensional arrays in C are allocated in row-major format. Traversing arrays in column major format will tend to make you have more cache misses and make your program more memory bound than processor bound:
#define N 1000000;
int matrix[N][N] = { ... }...
What are the dangers when creating a thread with a stack size of 50x the default?
...f the data ( float[] s) that I'll be accesing onto the stack (using stackalloc ).
8 Answers
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Practical use of `stackalloc` keyword
Has anyone ever actually used stackalloc while programming in C#? I am aware of what is does, but the only time it shows up in my code is by accident, because Intellisense suggests it when I start typing static , for example.
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What is the memory consumption of an object in Java?
... tell you, so long as the program gives the same answers.
It might allocate some temporary Objects on the stack.
It may optimize some variables or method calls totally out of existence replacing them with constants.
It might version methods or loops, i.e. compile two versions of a meth...
C++ Object Instantiation
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On the contrary, you should always prefer stack allocations, to the extent that as a rule of thumb, you should never have new/delete in your user code.
As you say, when the variable is declared on the stack, its destructor is automatically called when it goes out of scope...