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How to remove certain characters from a string in C++?
... string str("(555) 555-5555");
char chars[] = "()-";
for (unsigned int i = 0; i < strlen(chars); ++i)
{
// you need include <algorithm> to use general algorithms like std::remove()
str.erase (std::remove(str.begin(), str.end(), chars[i]), str.end());
}
// outpu...
Modern way to filter STL container?
...
See the example from cplusplus.com for std::copy_if:
std::vector<int> foo = {25,15,5,-5,-15};
std::vector<int> bar;
// copy only positive numbers:
std::copy_if (foo.begin(), foo.end(), std::back_inserter(bar), [](int i){return i>=0;} );
std::copy_if evaluates the lambda expr...
DateTime vs DateTimeOffset
... it in UTC (e.g. using DateTime.UtcNow ), and whenever we display one, we convert back from UTC to the user's local time.
...
KeyValuePair VS DictionaryEntry
...n Chris' example (in which we have two dictionaries containing <string, int> pairs).
Dictionary<string, int> dict = new Dictionary<string, int>();
foreach (KeyValuePair<string, int> item in dict) {
int i = item.Value;
}
Hashtable hashtable = new Hashtable();
foreach (Dict...
How do you implement a re-try-catch?
...
You need to enclose your try-catch inside a while loop like this: -
int count = 0;
int maxTries = 3;
while(true) {
try {
// Some Code
// break out of loop, or return, on success
} catch (SomeException e) {
// handle exception
if (++count == maxTries) th...
What is the most efficient way of finding all the factors of a number in Python?
...urn set(reduce(list.__add__,
([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0)))
This will return all of the factors, very quickly, of a number n.
Why square root as the upper limit?
sqrt(x) * sqrt(x) = x. So if the two factors are the same, they're both the square ro...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
...t is best to concentrate on where curly braces and parenthesis can be used interchangeably: when passing parameters to method calls. You may replace parenthesis with curly braces if, and only if, the method expects a single parameter. For example:
List(1, 2, 3).reduceLeft{_ + _} // valid, single Fun...
Are C# events synchronous?
... the order they are subscribed to the event.
I too was curious about the internal mechanism of event and its related operations. So I wrote a simple program and used ildasm to poke around its implementation.
The short answer is
there's no asynchronous operation involved in subscribing or invok...
Single controller with multiple GET methods in ASP.NET Web API
...troller}", new { action = "Get" }, new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) });
routes.MapHttpRoute("DefaultApiPost", "Api/{controller}", new {action = "Post"}, new {httpMethod = new HttpMethodConstraint(HttpMethod.Post)});
I verified this solution with the test class below. I ...
How can I get the line number which threw exception?
...
C# one liner: int line = (new StackTrace(ex, true)).GetFrame(0).GetFileLineNumber();
– gunwin
Aug 23 '13 at 12:15
...