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Why historically do people use 255 not 256 for database field magnitudes?
...char data (unless constrained otherwise). Most systems treat such an empty string as distinct from NULL, but some systems (notably Oracle) treat an empty string identically to NULL. For systems where an empty string is not NULL, an additional bit somewhere in the row would be needed to indicate whet...
Count character occurrences in a string in C++
How can I count the number of "_" in a string like "bla_bla_blabla_bla" ?
13 Answers
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How can we match a^n b^n with Java regex?
...'s start with a simpler problem: we want to match a+ at the beginning of a string, but only if it's followed immediately by b+. We can use ^ to anchor our match, and since we only want to match the a+ without the b+, we can use lookahead assertion (?=…).
Here is our pattern with a simple test harn...
Best way to parseDouble with comma as decimal separator?
..." it will happily return 1.23 without indicating to you that the passed-in String contained non-parsable characters. In some situations that might actually be desirable, but I don't think it's usually the desired behavior.
– E-Riz
Jan 17 '13 at 19:37
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C++ new int[0] — will it allocate memory?
...
I guarantee you that new int[0] costs you extra space since I have tested it.
For example,
the memory usage of
int **arr = new int*[1000000000];
is significantly smaller than
int **arr = new int*[1000000000];
for(int i =0; i < 1000000000; i++) {
arr[i]...
Why is “a” != “a” in C?
...
What you are comparing are the two memory addresses for the different strings, which are stored in different locations. Doing so essentially looks like this:
if(0x00403064 == 0x002D316A) // Two memory locations
{
printf("Yes, equal");
}
Use the following code to compare two string values...
How to read a text file reversely with iterator in C#
...lt;/summary>
public sealed class ReverseLineReader : IEnumerable<string>
{
/// <summary>
/// Buffer size to use by default. Classes with internal access can specify
/// a different buffer size - this is useful for testing.
/// </summary>
...
What is move semantics?
...nderstand move semantics with example code. Let's start with a very simple string class which only holds a pointer to a heap-allocated block of memory:
#include <cstring>
#include <algorithm>
class string
{
char* data;
public:
string(const char* p)
{
size_t size =...
Declaring an unsigned int in Java
... original purpose of Java. But for example Smartphones do not dispose with extra memory. And they usually use Java, as far as I know. But well, I don't want to start a war between Java programers and the others.
– Tomáš Zato - Reinstate Monica
Jun 18 '13 at 8...
How to insert an element after another element in JavaScript without using a library?
... of the element such as events because outerHTML converts the element to a string. We need it because insertAdjacentHTML adds content from strings rather than elements.
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