Question

我有一个课程如下：

class Integer {

private $variable;

public function __construct($variable) {
   $this->varaible = $variable;
}

// Works with string only
public function __isString() {
 return $this->variable;
}

// Works only, If Im using the class as a function (i must use parenthesis)
public function __invoke() {
 return $this->variable;
}

}


$int = new Integer($variable);

我想和类一样使用变量，如：

$result = $int + 10;

我不知道，我该如何归还$int;？

Answer 1

PHP不支持重载运算符（这是您正在寻找的技术问题）。当其中一个操作数是+时，它不知道如何处理class Integer，并且没有办法教PHP做什么。您可以做的最好的是实施适当的方法：

class Integer {
    ..
    public function add(Integer $int) {
        return new Integer($this->variable + $int->variable);
    }
}

$a = new Integer(1);
$b = new Integer(2);
echo $a->add($b);

Answer 2

是的，请参阅php的call_users_func()页面的示例4;

#import "MoreController.h"
#import "Annotation.h"

@interface MoreController ()
@property (weak, nonatomic) IBOutlet MKMapView *mapView;
@property (strong, nonatomic) Annotation *destination;
@end

@implementation MoreController

- (void) makeOverlayPathBetweenConsecutiveLocation:(Annotation *)source toDest:(Annotation *)destination {
    MKMapPoint startPoint = MKMapPointForCoordinate(source.coordinate);
    MKMapPoint endPoint = MKMapPointForCoordinate(destination.coordinate);

    MKMapPoint *pointArray = malloc(sizeof(CLLocationCoordinate2D) * 2);
    pointArray[0] = startPoint;
    pointArray[1] = endPoint;
    MKPolyline *routeLine = [MKPolyline polylineWithPoints:pointArray count:2];
    [self.mapView addOverlay:routeLine];
}

- (CLLocationDirection) getDirection:(Annotation *)source toDest:(Annotation *)destination {
    CLLocation *startLocation = [source getLocation];
    CLLocation *endLocation = [destination getLocation];

    //Determine the direction
    double lat1 = startLocation.coordinate.latitude * M_PI / 180.0;
    double lon1 = startLocation.coordinate.longitude * M_PI / 180.0;
    double lat2 = endLocation.coordinate.latitude * M_PI / 180.0;
    double lon2 = endLocation.coordinate.longitude * M_PI / 180.0;

    double dLon = lon2 - lon1;
    double y = sin(dLon) * cos(lat2);
    double x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon);
    double radiansBearing = atan2(y, x);

    CLLocationDirection directionBetweenPoints = radiansBearing * 180.0 / M_PI;

    return directionBetweenPoints;
}


- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    CLLocationCoordinate2D sourceCoordinate = {
        51.0455555556,
        1.94722222222
    };

    CLLocationCoordinate2D destCoordinate = {
        51.0491666667,
        1.80805555556
    };

    Annotation *sourceAnnotation = [[Annotation alloc] initWithCoordinate:sourceCoordinate forTitle:@"Source" forSubTitle:@"From"];
    [sourceAnnotation setTypeOfAnnotation:PIN_ANNOTATION];

    Annotation *destAnnotation = [[Annotation alloc] initWithCoordinate:destCoordinate forTitle:@"Destination" forSubTitle:@"To"];
    [destAnnotation setTypeOfAnnotation:ARROW_ANNOTATION];

    [destAnnotation setDirection:[self getDirection:sourceAnnotation toDest:destAnnotation]];
    [self makeOverlayPathBetweenConsecutiveLocation:sourceAnnotation toDest:destAnnotation];

    [self.mapView addAnnotation:sourceAnnotation];
    [self.mapView addAnnotation:destAnnotation];
    [self.mapView setRegion:MKCoordinateRegionMake(destCoordinate, MKCoordinateSpanMake(0.3, 0.3))
                   animated:YES];

    self.destination = destAnnotation;
}

- (MKOverlayRenderer *) mapView:(MKMapView *) mapView viewForOverlay:(id) overlay {
    if ([overlay isKindOfClass:[MKPolyline class]]) {
        MKPolyline *route = overlay;
        MKPolylineRenderer *routeRenderer = [[MKPolylineRenderer alloc] initWithPolyline:route];
        routeRenderer.strokeColor = [UIColor blueColor];
        routeRenderer.lineWidth = 2.0;
        return routeRenderer;
    } else {
        return nil;
    }
}

//Determine the direction of arrow icon
- (UIImage*)rotatedImage:(UIImage*)sourceImage byDegreesFromNorth:(double)degrees {
    CGSize rotateSize =  sourceImage.size;
    UIGraphicsBeginImageContext(rotateSize);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, rotateSize.width/2, rotateSize.height/2);
    CGContextRotateCTM(context, ( degrees * M_PI/180.0 ) );
    CGContextScaleCTM(context, 1.0, -1.0);
    CGContextDrawImage(UIGraphicsGetCurrentContext(),
                       CGRectMake(-rotateSize.width/2,-rotateSize.height/2,rotateSize.width, rotateSize.height),
                       sourceImage.CGImage);
    UIImage *rotatedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return rotatedImage;
}

//Make custom annotaion pin if the annotation is of ship's current position
- (MKAnnotationView *) mapView:(MKMapView *) mapView viewForAnnotation: (id) annotation {
    MKAnnotationView *customAnnotationView;
    NSString *reuseId = @"custom";

    if ([annotation isKindOfClass:[Annotation class]]){
        Annotation *_annotation = (Annotation*)annotation;
        if ([[_annotation typeOfAnnotation] isEqualToString:PIN_ANNOTATION]) {
            customAnnotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
            [customAnnotationView setCanShowCallout:YES];
        } else {
            customAnnotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];

            //Determine the direction
            UIImage *arrowImage = [UIImage imageNamed:@"arrow"];
            double direction = [_annotation direction];
            [customAnnotationView setImage:[self rotatedImage:arrowImage byDegreesFromNorth:direction]];
            [customAnnotationView setCanShowCallout:YES];
        }
    } else {
        return nil;
    }

    return customAnnotationView;
}

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
    MKMapCamera *camera = self.mapView.camera;
    CLLocationDirection mapAngle = camera.heading;
    NSLog(@"map angle :  %f", mapAngle);

    if (mapAngle && (self.destination != nil)) {
        //Determine the arrow icon direction
        [self.mapView removeAnnotation:self.destination];
        [self.destination setDirection:mapAngle];
        [self.mapView addAnnotation:self.destination];
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Answer 3

cModule* parentmod = getParentModule(); cModule* mobilitymod = parentmod->getParentModule()->getSubmodule("mobility"); MassMobility* massMobilityMod = dynamic_cast<MassMobility*>(mobilitymod); EV<<"Current position is <<"massMobilityMod->getCurrentPosition(); 是不是这个错字？在$ this-＆gt; varaible？

是否可以在PHP中使用class作为变量？

3 个答案: