大约有 44,000 项符合查询结果（耗时：0.0200秒） [XML]
PostgreSQL: Difference between text and varchar (character varying)
What's the difference between the text data type and the character varying ( varchar ) data types?
9 Answers
...
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...
How do I lowercase a string in C?
...ent such a function. So yes, just loop through the string and convert each character to lowercase.
Something trivial like this:
#include <ctype.h>
for(int i = 0; str[i]; i++){
str[i] = tolower(str[i]);
}
or if you prefer one liners, then you can use this one by J.F. Sebastian:
for ( ;...
Test if characters are in a string
...
Use the grepl function
grepl(value, chars, fixed = TRUE)
# TRUE
Use ?grepl to find out more.
share
|
improve this answer
|
follow
...
How to check if a char is equal to an empty space?
...
if (c == ' ')
char is a primitive data type, so it can be compared with ==.
Also, by using double quotes you create String constant (" "), while with single quotes it's a char constant (' ').
...
What is the difference between char, nchar, varchar, and nvarchar in SQL Server?
What is meant by nvarchar ?
12 Answers
12
...
Why is char[] preferred over String for passwords?
In Swing, the password field has a getPassword() (returns char[] ) method instead of the usual getText() (returns String ) method. Similarly, I have come across a suggestion not to use String to handle passwords.
...
PHP: How to remove all non printable characters in a string?
I imagine I need to remove chars 0-31 and 127,
17 Answers
17
...
Pretty-print C++ STL containers
...t print a delimiter after the final item
template<typename T, typename TChar = char, typename TCharTraits = std::char_traits<TChar> >
class pretty_ostream_iterator : public std::iterator<std::output_iterator_tag, void, void, void, void>
{
public:
typedef TChar char_type;
ty...
Most efficient way to remove special characters from string
I want to remove all special characters from a string. Allowed characters are A-Z (uppercase or lowercase), numbers (0-9), underscore (_), or the dot sign (.).
...