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Hidden Features of MySQL
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Binary Protocol:
MySQL 4.1 introduced a binary protocol that allows non-string data values to be sent
and returned in native format without conversion to and from string format. (Very usefull)
Aside, mysql_real_query() is faster than mysql_query() because it does not call strlen()
to opera...
Remove spaces from std::string in C++
What is the preferred way to remove spaces from a string in C++? I could loop through all the characters and build a new string, but is there a better way?
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PHP random string generator
I'm trying to create a randomized string in PHP, and I get absolutely no output with this:
59 Answers
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When should I use malloc in C and when don't I?
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char *some_memory = "Hello World";
is creating a pointer to a string constant. That means the string "Hello World" will be somewhere in the read-only part of the memory and you just have a pointer to it. You can use the string as read-only. You cannot make changes to it. Example:
some_...
C++ deprecated conversion from string constant to 'char*'
...ver you have a situation like the following:
char* pointer_to_nonconst = "string literal";
Why? Well, C and C++ differ in the type of the string literal. In C the type is array of char and in C++ it is constant array of char. In any case, you are not allowed to change the characters of the string...
Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
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Q: What is the difference 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
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Clean code to printf size_t in C++ (or: Nearest equivalent of C99's %z in C++)
...l combine it with IOStreams to get type-safe behavior:
size_t foo = bar;
ostringstream os;
os << foo;
printf("%s", os.str().c_str());
It's not super-efficient, but your case above deals with file I/O, so that's your bottleneck, not this string formatting code.
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how to convert from int to char*?
...:to_chars(str.data(), str.data() + str.size(), 42);
In C++11, use std::to_string as:
std::string s = std::to_string(number);
char const *pchar = s.c_str(); //use char const* as target type
And in C++03, what you're doing is just fine, except use const as:
char const* pchar = temp_str.c_str(); /...
How to represent empty char in Java Character class
I want to represent an empty character in Java as "" in String...
15 Answers
15
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Code for decoding/encoding a modified base64 URL
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@Kirk: If it adds 3 characters then the base64 string is already corrupt. I guess it would be a good idea to validate the string, it should only contain the characters expected and Length % 4 != 3.
– AnthonyWJones
Aug 4 '09 at 17:36...