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Why is conversion from string constant to 'char*' valid in C but invalid in C++
...d implicit conversion--a string literal should be treated as being of type char const *, since you can't modify its contents (without causing undefined behavior).
As of C++11, the implicit conversion that had been deprecated was officially removed, so code that depends on it (like your first exampl...
iterating over each character of a String in ruby 1.8.6 (each_char)
I am new to ruby and currently trying to operate on each character separately from a base String in ruby. I am using ruby 1.8.6 and would like to do something like:
...
What data type to use for hashed password field and what length?
...h = password_hash("rasmuslerdorf", PASSWORD_DEFAULT);
The result is a 60-character string similar to the following (but the digits will vary, because it generates a unique salt).
$2y$10$.vGA1O9wmRjrwAVXD98HNOgsNpDczlqm3Jq7KnEd1rVAGv3Fykk1a
Use the SQL data type CHAR(60) to store this encoding o...
const char *, char const *, char * const 异同？const修饰符各位置有何区...
const char * p = new char('a'); 这个是常字符，即p的内容不能被修改。
char const * p 意义同上，没有区别。
这时，*p = 'c'; 会报错。
char * const p = new char('a'); 这个是常指针，即p指针本身不可被修改。
这时，p = new char; 会报...
Using backticks around field names
...backticks, I would assume it lets you get away with ridiculous stuff like
SELECT `id`, `my name`, `another field` , `field,with,comma`
Which does of course generate badly named tables.
If you're just being concise I don't see a problem with it,
you'll note if you run your query as such
EXPLA...
Difference between BYTE and CHAR in column datatypes
...
Let us assume the database character set is UTF-8, which is the recommended setting in recent versions of Oracle. In this case, some characters take more than 1 byte to store in the database.
If you define the field as VARCHAR2(11 BYTE), Oracle can us...
How do I tokenize a string in C++?
...enizer.hpp>
using namespace std;
using namespace boost;
int main(int, char**)
{
string text = "token, test string";
char_separator<char> sep(", ");
tokenizer< char_separator<char> > tokens(text, sep);
BOOST_FOREACH (const string& t, tokens) {
cou...
How can I validate a string to only allow alphanumeric characters in it?
...n I validate a string using Regular Expressions to only allow alphanumeric characters in it?
10 Answers
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Convert character to ASCII numeric value in java
I have String name = "admin";
then I do String charValue = name.substring(0,1); //charValue="a"
22 Answers
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strdup() - what does it do in C?
...'s a POSIX thing), it's effectively doing the same as the following code:
char *strdup(const char *src) {
char *dst = malloc(strlen (src) + 1); // Space for length plus nul
if (dst == NULL) return NULL; // No memory
strcpy(dst, src); // Copy the characters...