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How to handle back button in activity
... // your code.
}
older than API 5
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
// your code
return true;
}
return super.onKeyDown(keyCode, event);
}
...
How to break out or exit a method in Java?
...em.exit(0);
Java language provides three jump statemnts that allow you to interrupt the normal flow of program.
These include break , continue ,return ,labelled break statement
for e.g
import java.util.Scanner;
class demo
{
public static void main(String args[])
{
outerLo...
Is there a standard sign function (signum, sgn) in C/C++?
...one has posted the type-safe C++ version yet:
template <typename T> int sgn(T val) {
return (T(0) < val) - (val < T(0));
}
Benefits:
Actually implements signum (-1, 0, or 1). Implementations here using copysign only return -1 or 1, which is not signum. Also, some implementations...
How to decode Unicode escape sequences like “\u00ed” to proper UTF-8 encoded characters?
...lace_callback('/\\\\u([0-9a-fA-F]{4})/', function ($match) {
return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UCS-2BE');
}, $str);
In case it's UTF-16 based C/C++/Java/Json-style:
$str = preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/', function ($match) {
return mb_convert_enco...
How can I multiply and divide using only bit shifting and adding?
...ion)
(_2 means base 2)
As you can see, multiplication can be decomposed into adding and shifting and back again. This is also why multiplication takes longer than bit shifts or adding - it's O(n^2) rather than O(n) in the number of bits. Real computer systems (as opposed to theoretical computer s...
How to make exe files from a node.js app?
...k Batch File Compiler (commercial)
BoxedApp Packer
"Advanced" Batch To EXE Converter" (freeware)
Most will require you to keep the batch file as main executable, and then bundle node.exe and your scripts.
Depending on your script, you also have the option to port it to JSDB, which supports an eas...
What is the best way to use a HashMap in C++?
...by the key, insert and access is in O(log n). Usually the standard library internally uses red black trees for ordered maps. But this is just an implementation detail. In an unordered map insert and access is in O(1). It is just another name for a hashtable.
An example with (ordered) std::map:
#in...
MySQL JOIN the most recent row only?
... a synonym for INNER JOIN.
Test case:
CREATE TABLE customer (customer_id int);
CREATE TABLE customer_data (
id int,
customer_id int,
title varchar(10),
forename varchar(10),
surname varchar(10)
);
INSERT INTO customer VALUES (1);
INSERT INTO customer VALUES (2);
INSERT INTO custo...
How to suppress scientific notation when printing float values?
...o say, "you manage the display of precision yourself." The actual (Python internal) precision isn't changed, as is often done in other languages.
– JS.
Aug 22 '12 at 20:42
ad...
Calling C/C++ from Python?
...
You should have a look at Boost.Python. Here is the short introduction taken from their website:
The Boost Python Library is a framework for interfacing Python and
C++. It allows you to quickly and seamlessly expose C++ classes
functions and objects to Python, and vice-versa...