array_sum

Returns the sum of values in an array.

PHP

$a = array(2, 4, 6, 8);
echo array_sum($a);
// => 20

Ruby

a_var = [2, 4, 6, 8];
puts a_var.inject {|sum,x| sum ? sum + x : x };
# => 20

In the code above, the return value from the ruby code will be nil if the array used is empty. This is not exactly the same behaviour as PHP, since the array_sum() function will always return a number. We can force ruby to always return a float (or an int) too, even if the array is empty, by adding a bit of type casting to the final result:

Ruby

a_var = [];
puts a_var.inject {|sum,x| sum ? sum + x : x }.to_f;
# => 0.0

pi

Returns the value of PI to 14 (default) decimal places. This precision can be altered in the php.ini file.

PHP

echo pi();
// => 3.1415926535898

Ruby

puts Math::PI;
# => 3.14159265358979

In the code above, PI is actually a constant of the Module Math. PHP also has a constant which stores the approximate value of PI - M_PI.

PHP

echo M_PI();
// => 3.1415926535898

abs

Returns the absolute value for a number.

PHP

echo abs(-4.2);
// => 4.2;

Ruby

puts -4.2.abs;
# => 4.2;

acos

Returns the arc cosine of the argument provided in radians.

PHP

echo acos(0.7);
// => 0.79539883018414;

Ruby

puts Math.acos(0.7);
# => 0.79539883018414;

cos

Returns the cosine of the argument provided in radians.

PHP

echo cos(0.5);
// => 0.87758256189037;

Ruby

puts Math.cos(0.5);
# => 0.877582561890373;

ceil

Returns the next highest integer value by rounding up the argument provided.

PHP

echo ceil(4.1);
// => 5

Ruby

puts 4.1.ceil;
# => 5