大约有 44,000 项符合查询结果（耗时：0.0295秒） [XML]
Import CSV file to strongly typed data structure in .Net [closed]
...tring);
objConn.Open();
DataTable dt = new DataTable();
OleDbCommand objCmdSelect = new OleDbCommand("SELECT * FROM file.csv", objConn);
OleDbDataAdapter objAdapter1 = new OleDbDataAdapter();
objAdapter1.SelectCommand = objCmdSelect;
objAdapter1.Fill(dt);
objConn.Close();
...
Difference between char* and const char*?
...
char* is a mutable pointer to a mutable character/string.
const char* is a mutable pointer to an immutable character/string. You cannot change the contents of the location(s) this pointer points to. Also, compilers are requi...
Is char signed or unsigned by default?
In the book "Complete Reference of C" it is mentioned that char is by default unsigned.
7 Answers
...
What is the difference between char s[] and char *s?
...
The difference here is that
char *s = "Hello world";
will place "Hello world" in the read-only parts of the memory, and making s a pointer to that makes any writing operation on this memory illegal.
While doing:
char s[] = "Hello world";
puts the...
How do I trim leading/trailing whitespace in a standard way?
... allocated. The return
// value must NOT be deallocated using free() etc.
char *trimwhitespace(char *str)
{
char *end;
// Trim leading space
while(isspace((unsigned char)*str)) str++;
if(*str == 0) // All spaces?
return str;
// Trim trailing space
end = str + strlen(str) - 1;
...
How to convert a number to string and vice versa in C++
...ersion succeeded and idx is not 0, idx will contain the index of the first character that was not used for decoding. This could be an index behind the last character.
Finally, the integral types allow to specify a base, for digits larger than 9, the alphabet is assumed (a=10 until z=35). You can fi...
How to split a string with any whitespace chars as delimiters
...lit() to split a String into an Array of substrings using all whitespace characters ( ' ' , '\t' , '\n' , etc.) as delimiters?
...
Getting the encoding of a Postgres database
...
A programmatic solution:
SELECT pg_encoding_to_char(encoding) FROM pg_database WHERE datname = 'yourdb';
share
|
improve this answer
|
...
Printing hexadecimal characters in C
I'm trying to read in a line of characters, then print out the hexadecimal equivalent of the characters.
7 Answers
...
What are the mechanics of short string optimization in libc++?
...th:
1 bit goes to the long/short flag.
7 bits goes to the size.
Assuming char, 1 byte goes to the trailing null (libc++ will always store a trailing null behind the data).
This leaves 3 words minus 2 bytes to store a short string (i.e. largest capacity() without an allocation).
On a 32 bit mach...