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What are the differences between a pointer variable and a reference variable in C++?
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A pointer can be re-assigned:
int x = 5;
int y = 6;
int *p;
p = &x;
p = &y;
*p = 10;
assert(x == 5);
assert(y == 10);
A reference cannot, and must be assigned at initialization:
int x = 5;
int y = 6;
int &r = x...
How to validate an e-mail address in swift?
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I would use NSPredicate:
func isValidEmail(_ email: String) -> Bool {
let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
return em...
Jquery mouseenter() vs mouseover()
...nderstand the difference between the mouseenter() and mouseover() . The post states
7 Answers
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Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
...ence between these initializations?
char a[] = "string literal";
char *p = "string literal";
My program crashes if I try to assign a new value to p[i].
A: A string literal (the formal term
for a double-quoted string in C
source) can be used in two slightly
different ways:
A...
Join/Where with LINQ and Lambda
...e LINQ query syntax is much clearer, more natural, and makes it easier to spot errors:
var id = 1;
var query =
from post in database.Posts
join meta in database.Post_Metas on post.ID equals meta.Post_ID
where post.ID == id
select new { Post = post, Meta = meta };
If you're really stuc...
Using Java to find substring of a bigger string using Regular Expression
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You should be able to use non-greedy quantifiers, specifically *?. You're going to probably want the following:
Pattern MY_PATTERN = Pattern.compile("\\[(.*?)\\]");
This will give you a pattern that will match your string and put the text within the square brackets in the...
Real mouse position in canvas [duplicate]
...as, but the only way that it seems to work well is if the canvas is in the position 0,0 (upper left corner) if I change the canvas position, for some reason it doesn't draw like it should. Here is my code.
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Implementation difference between Aggregation and Composition in Java
I'm aware of the conceptual differences between Aggregation and Composition. Can someone tell me the implementation difference in Java between them with examples?
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How to restore the permissions of files and directories within git if they have been modified?
I have a git checkout. All the file permissions are different than what git thinks they should be therefore they all show up as modified.
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Calling C++ class methods via a function pointer
How do I obtain a function pointer for a class member function, and later call that member function with a specific object? I’d like to write:
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