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Efficient string concatenation in C++
I heard a few people expressing worries about "+" operator in std::string and various workarounds to speed up concatenation. Are any of these really necessary? If so, what is the best way to concatenate strings in C++?
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Max length UITextField
...ollowing implementation of textField(_:shouldChangeCharactersIn:replacementString:) method that is part of the UITextFieldDelegate protocol:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let textFieldText =...
generating GUID without hyphen
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Note that you are talking about the (canonical) string representation of a Guid. The Guid itself is actually a 128-bit integer value.
You can use the "N" specifier with the Guid.ToString(String) overload.
Guid.NewGuid().ToString("N");
By default letters are lowercase. ...
How do I get user IP address in django?
How do I get user's IP in django?
11 Answers
11
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Pointer to pointer clarification
...an address, it returns the object at that memory address. So when you do *ipp = ip2, what you are doing is *ipp get the object at the address held in ipp which is ip1 and then assign to ip1 the value stored in ip2, which is the address of j.
Simply
& --> Address of
* --> Value at
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Test if remote TCP port is open from a shell script
...ard with alpine linux and ubuntu both. probably others. no need to install extra when you're remoted in and can't. thanks for this! I might add, nc host port -w 2 && echo it works
– std''OrgnlDave
Apr 10 '17 at 14:34
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Split value from one field to two
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Unfortunately MySQL does not feature a split string function. However you can create a user defined function for this, such as the one described in the following article:
MySQL Split String Function by Federico Cargnelutti
With that function:
DELIMITER $$
CREATE ...
Get the client IP address using PHP [duplicate]
I want to get the client IP address who uses my website. I am using the PHP $_SERVER superglobal:
5 Answers
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Remove leading or trailing spaces in an entire column of data
...ong - TRIM appears to be eliminating duplicated spaces in the middle of my string. Is there a way to only trim off leading and trailing spaces?
– Shavais
Oct 16 '15 at 15:17
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C++ : why bool is 8 bits long?
...or booleans, in a way. I seem to remember Pascal implementing sets as bit strings. That is, for the following set:
{1, 2, 5, 7}
You might have this in memory:
01100101
You can, of course, do something similar in C / C++ if you want. (If you're keeping track of a bunch of booleans, it could ...