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How to check if an int is a null
... 0
long 0L
float 0.0f
double 0.0d
char '\u0000'
boolean false
Objects have null as default value.
String (or any object)--->null
1.) I need to check if the object is not null; Is the following expression correct;
if (person == n...
Can we make unsigned byte in Java
... for the `unsignedByte` variable,
* i.e. `short`, `int`, `long` and even `char`, but during bitwise operations
* it would get casted to `int` anyway.
*/
void printUnsignedByte(byte b) {
int unsignedByte = b & 0xFF;
System.out.println(unsignedByte); // "200"
}
...
Test whether string is a valid integer
...sonably elegant) way of doing this - I don't want to have to pick it apart char by char.
11 Answers
...
What is a non-capturing group in regular expressions?
...over it:
\b(\S)(\S)(\S)(\S*)\b
This regex matches words with at least 3 characters, and uses groups to separate the first three letters. The result is this:
Match "Lorem"
Group 1: "L"
Group 2: "o"
Group 3: "r"
Group 4: "em"
Match "ipsum"
Group 1: "i"
Group 2: "p"
...
How do I read an entire file into a std::string in C++?
...os_type fileSize = ifs.tellg();
ifs.seekg(0, ios::beg);
vector<char> bytes(fileSize);
ifs.read(bytes.data(), fileSize);
return string(bytes.data(), fileSize);
}
This solution resulted in about 20% faster execution times than the other answers presented here, when taking the...
Is Using .NET 4.0 Tuples in my C# Code a Poor Design Decision?
...pport for tuples in C#:
private var GetDesserts()
{
return _icecreams.Select(
i => new { icecream = i, topping = new Topping(i) }
);
}
public void Eat()
{
foreach (var dessert in GetDesserts())
{
dessert.icecream.AddTopping(dessert.topping);
dessert.Eat()...
Executing a command stored in a variable from PowerShell
...h was included, verify that the path is correct and try again. At :line:14 char:1 + & <<<< $cmd1
– Travis
Aug 28 '10 at 23:29
...
What's the difference between backtracking and depth first search?
...to searching tree structures. From Wikipedia:
One starts at the root (selecting some node as the root in the graph case) and explores as far as possible along each branch before backtracking.
It uses backtracking as part of its means of working with a tree, but is limited to a tree structure....
Efficient way to determine number of digits in an integer
...cialization optimization for 8-bit numbers
template <>
int numDigits(char n)
{
// if you have the time, replace this with a static initialization to avoid
// the initial overhead & unnecessary branch
static char x[256] = {0};
if (x[0] == 0) {
for (char c = 1; c != 0...
Efficiently convert rows to columns in sql server
...ou can use the PIVOT function to transform the data from rows to columns:
select Firstname, Amount, PostalCode, LastName, AccountNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
S...