trait HelloWorld { public function sayHello() { echo 'Hello '; }   public function sayWorld() { echo 'World!'; } }   class MyClass { use HelloWorld; public function sayHelloWorld() { $this->sayhello(); $this->sayWorld(); } }   $h = new MyClass(); $h->sayHelloWorld(); // outputs "Hello World!"

In implementing traits, the keywords trait and insteadof were added to PHP. Usage of trait is outlined above. The PHP keyword insteadof is used for conflict resolution. Here’s an example of how to use insteadof:

trait A { public function smallTalk() { echo 'a'; } public function bigTalk() { echo 'A'; } }   trait B { public function smallTalk() { echo 'b'; } public function bigTalk() { echo 'B'; } }   class Talker { use A, B { B::smallTalk insteadof A; A::bigTalk insteadof B; } }   class Aliased_Talker { use A, B { B::smallTalk insteadof A; A::bigTalk insteadof B; B::bigTalk as talk; } }

<? $res = "";   $f = new NumberFormatter("en", NumberFormatter::SPELLOUT);   for($i = 1; $i format($i)); if($i > 100 && $i % 100 != 0) { $res .= 'and'; } } echo strlen($res)."\n";

My first submission was incorrect and I quickly figured out it was because the NumberFormatter class was missing the “and” after the hundreds. I simply added that at the end since we’re only looking for a count and came up with the correct result. Installing the NumberFormatter class in Debian squeeze was pretty easy. I simply had to install the PHP5 international compatibility package: sudo apt-get instal php5-intl

var_dump(25/7); // float(3.5714285714286) var_dump((int) (25/7)); // int(3) var_dump(round(25/7)); // float(4)

/** * Calculate the sum of all the primes below two million. **/

include

include

using namespace std;   bool isPrime(long num) { if(num<=1) return false; for(long i=2; i<=sqrt(num*1.0); i++) { if(num%i==0) return false; } return true; }   int main () { long upperlimit = 2000000, sum = 0;   for (long i = 2; i < upperlimit; i++) { if(isPrime(i)) { sum += i; cout << "Prime found: " << i << endl; } }   cout << "The sum of primes below " << upperlimit << " is " << sum << endl;   return (0); }

The interesting part of this problem for me was I updated my primality test to include the fact that if a number n has a factor greater than sqrt(n) it must also have one less than sqrt(n), so we only have to test up to sqrt(n) in our primality test:

bool isPrime(long num) { if(num<=1) return false; for(long i=2; i<=sqrt(num*1.0); i++) { if(num%i==0) return false; } return true; }

include

using namespace std;   int main () {   for(int a = 1; a < 1000; a++) { for(int b = 1; b < 1000; b++) { cout << "a: " << a << " b: " << b << " c: " << (1000 - a - b) << " a^2 + b^2: " << (a * a + b * b) << " c^2: " << (1000 - a - b) * (1000 - a - b) << endl; if(a * a + b * b == (1000 - a - b) * (1000 - a - b)) { return (0); } } } return (0); }

There you have it, the program stops at a^2 + b^2 = c^2 where c = (1000 – a – b). I then took abc to get the answer.

/** * Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum. **/

include

using namespace std;   bool isPrime ( unsigned long num ) { for(int i = num - 1; i > 1; i--) { if(num % i == 0) { return false; } } return true; }   int main () { unsigned long num = 2, primeCount = 0;   while ( primeCount < 10001 ) { if ( isPrime (num) ) { primeCount++; cout << "Prime " << primeCount << " " << num << " is prime" << endl; } num++; }   return(0); }

/** * Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum. **/

include

using namespace std;   bool isPrime ( unsigned long num ) { for(int i = num - 1; i > 1; i--) { if(num % i == 0) { return false; } } return true; }   int main () { unsigned long num = 2, primeCount = 0;   while ( primeCount < 10001 ) { if ( isPrime (num) ) { primeCount++; cout << "Prime " << primeCount << " " << num << " is prime" << endl; } num++; }   return(0); }

include

using namespace std;   int main () { unsigned long sumsquares = 0, sums = 0; int n;   cout <> n;   while (n < 0) { cout <> n; }   for(int i = 1; i <= n; i++) { cout << "i: " << i << endl; sumsquares += i * i; cout << "sumsquares: " << sumsquares << endl; sums += i; cout << "sums: " << sums << endl; }   cout << "The sum of squares from 1 to " << n << ": " << sumsquares << endl; cout << "The square of sums from 1 to " << n << ": " << sums * sums << endl << endl; cout << "The difference: " << (sums * sums - sumsquares) << endl;   return(0); }

As you can see, there is a loop creating the sum and the sum of squares. From there, it subtracts the square of the sum and the sum of squares to get the answer.

include

using namespace std;   unsigned long gcd(unsigned long a, unsigned long b) { if(b == 0) return a; return gcd(b, a%b); }   unsigned long lcm(unsigned long a, unsigned long b) { return a * b / gcd(a,b); }   int main () { unsigned long answer = 1; for(long i = 1; i <= 20; i++) { cout << "i: " << i; answer = lcm(answer, i); cout << " lcm: " << answer << endl; }   return 0; }

My solution uses an algorithm to compute the least common multiple that involves finding the greatest common divisor as follows: lcm(a, b) = a*b / gcd(a, b). I used the Euclid method of finding the greatest common divisor: gcd(a,0) = a; gcd(a, b) = gcd(b, a mod b).

function recently_modified_dashboard_widget_function() { global $wpdb;   $querystr = " SELECT $wpdb->posts.* FROM $wpdb->posts WHERE $wpdb->posts.post_type = 'page' ORDER BY $wpdb->posts.post_modified DESC LIMIT 0,25 ";   echo "<ul>\n"; foreach($wpdb->get_results($querystr, OBJECT) as $post) { echo '<li>'.edit_post_link( str_replace( site_url(), '', get_permalink( $post->ID ) ), '', '', $post->ID )."</a></li>\n"; } echo "</ul>\n"; }

The query gets the last 25 posts of type page ordered by post_modified. From there, a foreach loop through the result yields individual posts in object form. The I used the post’s permalink, stripping off the site_url() as the text for the edit_post_link() text. All is well. I’ll soon publish the plugin which adds the list to the admin dashboard.