Лекция. ООП в php
Класс — это описание объектов определенного типа.
На основе классов создаются объекты. Может быть множество объектов, принадлежащих одному классу. С другой стороны, может быть класс без объектов, реализованных на его основе.
Преимущества ООП проявляются при использовании множества объектов одного класса.
Описание классов в PHP начинаются служебным словом class:
class Имя_класса {
// описание членов класса - данных и методов для их обработки
}
Для объявления объекта необходимо использовать оператор new:
Объект = new Имя_класса;
Данные описываются с помощью служебного слова var. Метод описывается так же, как и обыкновенная функция. Методу также можно передавать параметры.
<?php
class MyClass
{
// данные (свойства):
var $name;
var $addr;
// методы:
function result () {
echo "<h3>ееееее</h3>";
}
}
// Создаем два объекта
$objekt1 = new MyClass;
$objekt2= new MyClass;
// Получаем значения ф-ии для этих объектов
echo $objekt1 ->result();
echo $objekt2-> result ();
?>
Ниже показан класс фазы луны и использование этого класса. Если в папке разместить картинки с фазами луны( 21.jpg), название которых соответствует дню цикла, на экран будет выводится соответствующая картинка.
<?php /** * Moon phase calculation class * Adapted for PHP from Moontool for Windows (http://www.fourmilab.ch/moontoolw/) * by Samir Shah (http://rayofsolaris.net) * License: MIT **/ namespace Solaris; class MoonPhase { private $timestamp; private $phase; private $illum; private $age; private $dist; private $angdia; private $sundist; private $sunangdia; private $synmonth; private $quarters = null; function __construct( $pdate = null ) { if( is_null( $pdate ) ) $pdate = time(); /* Astronomical constants */ $epoch = 2444238.5; // 1980 January 0.0 /* Constants defining the Sun's apparent orbit */ $elonge = 278.833540; // Ecliptic longitude of the Sun at epoch 1980.0 $elongp = 282.596403; // Ecliptic longitude of the Sun at perigee $eccent = 0.016718; // Eccentricity of Earth's orbit $sunsmax = 1.495985e8; // Semi-major axis of Earth's orbit, km $sunangsiz = 0.533128; // Sun's angular size, degrees, at semi-major axis distance /* Elements of the Moon's orbit, epoch 1980.0 */ $mmlong = 64.975464; // Moon's mean longitude at the epoch $mmlongp = 349.383063; // Mean longitude of the perigee at the epoch $mlnode = 151.950429; // Mean longitude of the node at the epoch $minc = 5.145396; // Inclination of the Moon's orbit $mecc = 0.054900; // Eccentricity of the Moon's orbit $mangsiz = 0.5181; // Moon's angular size at distance a from Earth $msmax = 384401; // Semi-major axis of Moon's orbit in km $mparallax = 0.9507; // Parallax at distance a from Earth $synmonth = 29.53058868; // Synodic month (new Moon to new Moon) $this->synmonth = $synmonth; $lunatbase = 2423436.0; // Base date for E. W. Brown's numbered series of lunations (1923 January 16) /* Properties of the Earth */ // $earthrad = 6378.16; // Radius of Earth in kilometres // $PI = 3.14159265358979323846; // Assume not near black hole $this->timestamp = $pdate; // pdate is coming in as a UNIX timstamp, so convert it to Julian $pdate = $pdate / 86400 + 2440587.5; /* Calculation of the Sun's position */ $Day = $pdate - $epoch; // Date within epoch $N = $this->fixangle((360 / 365.2422) * $Day); // Mean anomaly of the Sun $M = $this->fixangle($N + $elonge - $elongp); // Convert from perigee co-ordinates to epoch 1980.0 $Ec = $this->kepler($M, $eccent); // Solve equation of Kepler $Ec = sqrt((1 + $eccent) / (1 - $eccent)) * tan($Ec / 2); $Ec = 2 * rad2deg(atan($Ec)); // True anomaly $Lambdasun = $this->fixangle($Ec + $elongp); // Sun's geocentric ecliptic longitude $F = ((1 + $eccent * cos(deg2rad($Ec))) / (1 - $eccent * $eccent)); // Orbital distance factor $SunDist = $sunsmax / $F; // Distance to Sun in km $SunAng = $F * $sunangsiz; // Sun's angular size in degrees /* Calculation of the Moon's position */ $ml = $this->fixangle(13.1763966 * $Day + $mmlong); // Moon's mean longitude $MM = $this->fixangle($ml - 0.1114041 * $Day - $mmlongp); // Moon's mean anomaly $MN = $this->fixangle($mlnode - 0.0529539 * $Day); // Moon's ascending node mean longitude $Ev = 1.2739 * sin(deg2rad(2 * ($ml - $Lambdasun) - $MM)); // Evection $Ae = 0.1858 * sin(deg2rad($M)); // Annual equation $A3 = 0.37 * sin(deg2rad($M)); // Correction term $MmP = $MM + $Ev - $Ae - $A3; // Corrected anomaly $mEc = 6.2886 * sin(deg2rad($MmP)); // Correction for the equation of the centre $A4 = 0.214 * sin(deg2rad(2 * $MmP)); // Another correction term $lP = $ml + $Ev + $mEc - $Ae + $A4; // Corrected longitude $V = 0.6583 * sin(deg2rad(2 * ($lP - $Lambdasun))); // Variation $lPP = $lP + $V; // True longitude $NP = $MN - 0.16 * sin(deg2rad($M)); // Corrected longitude of the node $y = sin(deg2rad($lPP - $NP)) * cos(deg2rad($minc)); // Y inclination coordinate $x = cos(deg2rad($lPP - $NP)); // X inclination coordinate $Lambdamoon = rad2deg(atan2($y, $x)) + $NP; // Ecliptic longitude $BetaM = rad2deg(asin(sin(deg2rad($lPP - $NP)) * sin(deg2rad($minc)))); // Ecliptic latitude /* Calculation of the phase of the Moon */ $MoonAge = $lPP - $Lambdasun; // Age of the Moon in degrees $MoonPhase = (1 - cos(deg2rad($MoonAge))) / 2; // Phase of the Moon // Distance of moon from the centre of the Earth $MoonDist = ($msmax * (1 - $mecc * $mecc)) / (1 + $mecc * cos(deg2rad($MmP + $mEc))); $MoonDFrac = $MoonDist / $msmax; $MoonAng = $mangsiz / $MoonDFrac; // Moon's angular diameter // $MoonPar = $mparallax / $MoonDFrac; // Moon's parallax // store results $this->phase = $this->fixangle($MoonAge) / 360; // Phase (0 to 1) $this->illum = $MoonPhase; // Illuminated fraction (0 to 1) $this->age = $synmonth * $this->phase; // Age of moon (days) $this->dist = $MoonDist; // Distance (kilometres) $this->angdia = $MoonAng; // Angular diameter (degrees) $this->sundist = $SunDist; // Distance to Sun (kilometres) $this->sunangdia = $SunAng; // Sun's angular diameter (degrees) } private function fixangle($a) { return ( $a - 360 * floor($a / 360) ); } // KEPLER -- Solve the equation of Kepler. private function kepler($m, $ecc) { $epsilon = 0.000001; // 1E-6 $e = $m = deg2rad($m); do { $delta = $e - $ecc * sin($e) - $m; $e -= $delta / ( 1 - $ecc * cos($e) ); } while ( abs($delta) > $epsilon ); return $e; } /* Calculates time of the mean new Moon for a given base date. This argument K to this function is the precomputed synodic month index, given by: K = (year - 1900) * 12.3685 where year is expressed as a year and fractional year. */ private function meanphase($sdate, $k){ // Time in Julian centuries from 1900 January 0.5 $t = ( $sdate - 2415020.0 ) / 36525; $t2 = $t * $t; $t3 = $t2 * $t; $nt1 = 2415020.75933 + $this->synmonth * $k + 0.0001178 * $t2 - 0.000000155 * $t3 + 0.00033 * sin( deg2rad( 166.56 + 132.87 * $t - 0.009173 * $t2 ) ); return $nt1; } /* Given a K value used to determine the mean phase of the new moon, and a phase selector (0.0, 0.25, 0.5, 0.75), obtain the true, corrected phase time. */ private function truephase($k, $phase){ $apcor = false; $k += $phase; // Add phase to new moon time $t = $k / 1236.85; // Time in Julian centuries from 1900 January 0.5 $t2 = $t * $t; // Square for frequent use $t3 = $t2 * $t; // Cube for frequent use $pt = 2415020.75933 // Mean time of phase + $this->synmonth * $k + 0.0001178 * $t2 - 0.000000155 * $t3 + 0.00033 * sin( deg2rad( 166.56 + 132.87 * $t - 0.009173 * $t2 ) ); $m = 359.2242 + 29.10535608 * $k - 0.0000333 * $t2 - 0.00000347 * $t3; // Sun's mean anomaly $mprime = 306.0253 + 385.81691806 * $k + 0.0107306 * $t2 + 0.00001236 * $t3; // Moon's mean anomaly $f = 21.2964 + 390.67050646 * $k - 0.0016528 * $t2 - 0.00000239 * $t3; // Moon's argument of latitude if ( $phase < 0.01 || abs( $phase - 0.5 ) < 0.01 ) { // Corrections for New and Full Moon $pt += (0.1734 - 0.000393 * $t) * sin( deg2rad( $m ) ) + 0.0021 * sin( deg2rad( 2 * $m ) ) - 0.4068 * sin( deg2rad( $mprime ) ) + 0.0161 * sin( deg2rad( 2 * $mprime) ) - 0.0004 * sin( deg2rad( 3 * $mprime ) ) + 0.0104 * sin( deg2rad( 2 * $f ) ) - 0.0051 * sin( deg2rad( $m + $mprime ) ) - 0.0074 * sin( deg2rad( $m - $mprime ) ) + 0.0004 * sin( deg2rad( 2 * $f + $m ) ) - 0.0004 * sin( deg2rad( 2 * $f - $m ) ) - 0.0006 * sin( deg2rad( 2 * $f + $mprime ) ) + 0.0010 * sin( deg2rad( 2 * $f - $mprime ) ) + 0.0005 * sin( deg2rad( $m + 2 * $mprime ) ); $apcor = true; } else if ( abs( $phase - 0.25 ) < 0.01 || abs( $phase - 0.75 ) < 0.01 ) { $pt += (0.1721 - 0.0004 * $t) * sin( deg2rad( $m ) ) + 0.0021 * sin( deg2rad( 2 * $m ) ) - 0.6280 * sin( deg2rad( $mprime ) ) + 0.0089 * sin( deg2rad( 2 * $mprime) ) - 0.0004 * sin( deg2rad( 3 * $mprime ) ) + 0.0079 * sin( deg2rad( 2 * $f ) ) - 0.0119 * sin( deg2rad( $m + $mprime ) ) - 0.0047 * sin( deg2rad ( $m - $mprime ) ) + 0.0003 * sin( deg2rad( 2 * $f + $m ) ) - 0.0004 * sin( deg2rad( 2 * $f - $m ) ) - 0.0006 * sin( deg2rad( 2 * $f + $mprime ) ) + 0.0021 * sin( deg2rad( 2 * $f - $mprime ) ) + 0.0003 * sin( deg2rad( $m + 2 * $mprime ) ) + 0.0004 * sin( deg2rad( $m - 2 * $mprime ) ) - 0.0003 * sin( deg2rad( 2 * $m + $mprime ) ); if ( $phase < 0.5 ) // First quarter correction $pt += 0.0028 - 0.0004 * cos( deg2rad( $m ) ) + 0.0003 * cos( deg2rad( $mprime ) ); else // Last quarter correction $pt += -0.0028 + 0.0004 * cos( deg2rad( $m ) ) - 0.0003 * cos( deg2rad( $mprime ) ); $apcor = true; } if (!$apcor) // function was called with an invalid phase selector return false; return $pt; } /* Find time of phases of the moon which surround the current date. Five phases are found, starting and ending with the new moons which bound the current lunation. */ private function phasehunt() { $sdate = $this->utctojulian( $this->timestamp ); $adate = $sdate - 45; $ats = $this->timestamp - 86400 * 45; $yy = (int) gmdate( 'Y', $ats ); $mm = (int) gmdate( 'n', $ats ); $k1 = floor( ( $yy + ( ( $mm - 1 ) * ( 1 / 12 ) ) - 1900 ) * 12.3685 ); $adate = $nt1 = $this->meanphase( $adate, $k1 ); while (true) { $adate += $this->synmonth; $k2 = $k1 + 1; $nt2 = $this->meanphase( $adate, $k2 ); // if nt2 is close to sdate, then mean phase isn't good enough, we have to be more accurate if( abs( $nt2 - $sdate ) < 0.75 ) $nt2 = $this->truephase( $k2, 0.0 ); if ( $nt1 <= $sdate && $nt2 > $sdate ) break; $nt1 = $nt2; $k1 = $k2; } // results in Julian dates $data = array( $this->truephase( $k1, 0.0 ), $this->truephase( $k1, 0.25 ), $this->truephase( $k1, 0.5 ), $this->truephase( $k1, 0.75 ), $this->truephase( $k2, 0.0 ), $this->truephase( $k2, 0.25 ), $this->truephase( $k2, 0.5 ), $this->truephase( $k2, 0.75 ) ); $this->quarters = array(); foreach( $data as $v ) $this->quarters[] = ( $v - 2440587.5 ) * 86400; // convert to UNIX time } /* Convert UNIX timestamp to astronomical Julian time (i.e. Julian date plus day fraction). */ private function utctojulian( $ts ) { return $ts / 86400 + 2440587.5; } private function get_phase( $n ) { if( is_null( $this->quarters ) ) $this->phasehunt(); return $this->quarters[$n]; } /* Public functions for accessing results */ function phase(){ return $this->phase; } function illumination(){ return $this->illum; } function age(){ return $this->age; } function distance(){ return $this->dist; } function diameter(){ return $this->angdia; } function sundistance(){ return $this->sundist; } function sundiameter(){ return $this->sunangdia; } function new_moon(){ return $this->get_phase( 0 ); } function first_quarter(){ return $this->get_phase( 1 ); } function full_moon(){ return $this->get_phase( 2 ); } function last_quarter(){ return $this->get_phase( 3 ); } function next_new_moon(){ return $this->get_phase( 4 ); } function next_first_quarter(){ return $this->get_phase( 5 ); } function next_full_moon(){ return $this->get_phase( 6 ); } function next_last_quarter(){ return $this->get_phase( 7 ); } function phase_name() { $names = array( 'New Moon', 'Waxing Crescent', 'First Quarter', 'Waxing Gibbous', 'Full Moon', 'Waning Gibbous', 'Third Quarter', 'Waning Crescent', 'New Moon' ); // There are eight phases, evenly split. A "New Moon" occupies the 1/16th phases either side of phase = 0, and the rest follow from that. return $names[ floor( ( $this->phase + 0.0625 ) * 8 ) ]; } } // create an instance of the class, and use the current time $moon = new MoonPhase(); $age = round( $moon->age(), 0 ); $stage = $moon->phase() < 0.5 ? 'waxing' : 'waning'; $distance = round( $moon->distance(), 2 ); $next = gmdate( 'G:i:s, j M Y', $moon->next_new_moon() ); echo "The moon is currently $age days old, and is therefore $stage. "; echo "It is $distance km from the centre of the Earth. "; echo "The next new moon is at $next."; echo "<img src='$age.png'>"; ?> |