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Size of character ('a') in C/C++
What is the size of character in C and C++ ? As far as I know the size of char is 1 byte in both C and C++.
4 Answers
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Get the new record primary key ID from MySQL insert query?
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Eg:
INSERT INTO table_name (col1, col2,...) VALUES ('val1', 'val2'...);
SELECT LAST_INSERT_ID();
This will get you back the PRIMARY KEY value of the last row that you inserted:
The ID that was generated is maintained in the server on a per-connection basis. This means that the value returne...
Is the sizeof(some pointer) always equal to four?
For example:
sizeof(char*) returns 4. As does int* , long long* , everything that I've tried. Are there any exceptions to this?
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How do I create a random alpha-numeric string in C++?
I'd like to create a random string, consisting of alpha-numeric characters. I want to be able to be specify the length of the string.
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How to find memory leak in a C++ code/project?
..., you should use a delete so that you free the same memory you allocated:
char* str = new char [30]; // Allocate 30 bytes to house a string.
delete [] str; // Clear those 30 bytes and make str point nowhere.
2
Reallocate memory only if you've deleted. In the code below, str acquires a new addre...
Regex to Match Symbols: !$%^&*()_+|~-=`{}[]:";'?,./
...al letters represent the negation of their lowercase counterparts.
\W will select all non "word" characters equivalent to [^a-zA-Z0-9_]
\S will select all non "whitespace" characters equivalent to [ \t\n\r\f\v]
_ will select "_" because we negate it when using the \W and need to add it back in
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C++ lambda with captures as a function pointer
...ector>
#include <functional>
using namespace std;
int ftw(const char *fpath, std::function<int (const char *path)> callback) {
return callback(fpath);
}
int main()
{
vector<string> entries;
std::function<int (const char *fpath)> callback = [&](const char *fpa...
Structure padding and packing
...s the following "gaps" into your first structure:
struct mystruct_A {
char a;
char gap_0[3]; /* inserted by compiler: for alignment of b */
int b;
char c;
char gap_1[3]; /* -"-: for alignment of the whole struct in an array */
} x;
Packing, on the other hand prevents compiler ...
Difference between String replace() and replaceAll()
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In java.lang.String, the replace method either takes a pair of char's or a pair of CharSequence's (of which String is a subclass, so it'll happily take a pair of String's). The replace method will replace all occurrences of a char or CharSequence. On the other hand, both String arguments...
Avoid trailing zeroes in printf()
...") the number to a string buffer then manipulate the string to only have N characters past the decimal point.
Assuming your number is in the variable num, the following function will remove all but the first N decimals, then strip off the trailing zeros (and decimal point if they were all zeros).
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