if([UIDevice currentDevice].userInterfaceIdiom==UIUserInterfaceIdiomPad) {
    //Device is ipad 
}else{
    //Device is iphone
}

Dutchie432和Brian Robbins提供了很好的解决方案。但还有一款型号没有推出，那就是Verizon的iPhone 4。这是缺失的一行。

if ([platform isEqualToString:@"iPhone3,2"])    return @"iPhone 4"; //Verizon

回答在Swift 3，

struct DeviceInformation {
    // UIDevice.current.model's value is "iPhone" or "iPad"，which does not include details; the following "model" is detailed, such as, iPhone7,1 is actually iPhone 6 plus
    static let model: String = {
        var size = 0
        sysctlbyname("hw.machine", nil, &size, nil, 0)
        var machine = [CChar](repeating: 0,  count: Int(size))
        sysctlbyname("hw.machine", &machine, &size, nil, 0)
        return String(cString: machine)
    }()

    static let uuid = UIDevice.current.identifierForVendor?.uuidString ?? ""
    static let idForAdService = ASIdentifierManager.shared().advertisingIdentifier.uuidString

    static func diviceTypeReadableName() -> String {
        switch model {
        case "iPhone1,1":   return "iPhone 1G"
        case "iPhone1,2":   return "iPhone 3G"
        case "iPhone2,1":   return "iPhone 3GS"
        case "iPhone3,1":   return "iPhone 4"
        case "iPhone3,3":   return "iPhone 4 (Verizon)"
        case "iPhone4,1":   return "iPhone 4S"
        case "iPhone5,1":   return "iPhone 5 (GSM)"
        case "iPhone5,2":   return "iPhone 5 (GSM+CDMA)"
        case "iPhone5,3":   return "iPhone 5c (GSM)"
        case "iPhone5,4":   return "iPhone 5c (GSM+CDMA)"
        case "iPhone6,1":   return "iPhone 5s (GSM)"
        case "iPhone6,2":   return "iPhone 5s (GSM+CDMA)"
        case "iPhone7,2":   return "iPhone 6"
        case "iPhone7,1":   return "iPhone 6 Plus"
        case "iPhone8,1":   return "iPhone 6s"
        case "iPhone8,2":   return "iPhone 6s Plus"
        case "iPhone8,4":   return "iPhone SE"
        case "iPhone9,1":   return "iPhone 7"
        case "iPhone9,3":   return "iPhone 7"
        case "iPhone9,2":   return "iPhone 7 Plus"
        case "iPhone9,4":   return "iPhone 7 Plus"
        case "iPod1,1":     return "iPod Touch 1G"
        case "iPod2,1":     return "iPod Touch 2G"
        case "iPod3,1":     return "iPod Touch 3G"
        case "iPod4,1":     return "iPod Touch 4G"
        case "iPod5,1":     return "iPod Touch 5G"
        case "iPod7,1":     return "iPod Touch 6G"
        case "iPad1,1":     return "iPad 1G"
        case "iPad2,1":     return "iPad 2 (Wi-Fi)"
        case "iPad2,2":     return "iPad 2 (GSM)"
        case "iPad2,3":     return "iPad 2 (CDMA)"
        case "iPad2,4":     return "iPad 2 (Wi-Fi)"
        case "iPad2,5":     return "iPad Mini (Wi-Fi)"
        case "iPad2,6":     return "iPad Mini (GSM)"
        case "iPad2,7":     return "iPad Mini (GSM+CDMA)"
        case "iPad3,1":     return "iPad 3 (Wi-Fi)"
        case "iPad3,2":     return "iPad 3 (GSM+CDMA)"
        case "iPad3,3":     return "iPad 3 (GSM)"
        case "iPad3,4":     return "iPad 4 (Wi-Fi)"
        case "iPad3,5":     return "iPad 4 (GSM)"
        case "iPad3,6":     return "iPad 4 (GSM+CDMA)"
        case "iPad4,1":     return "iPad Air (Wi-Fi)"
        case "iPad4,2":     return "iPad Air (Cellular)"
        case "iPad4,3":     return "iPad Air (China)"
        case "iPad4,4":     return "iPad Mini 2G (Wi-Fi)"
        case "iPad4,5":     return "iPad Mini 2G (Cellular)"
        case "iPad4,6":     return "iPad Mini 2G (China)"
        case "iPad4,7":     return "iPad Mini 3 (Wi-Fi)"
        case "iPad4,8":     return "iPad Mini 3 (Cellular)"
        case "iPad4,9":     return "iPad Mini 3 (China)"
        case "iPad5,1":     return "iPad Mini 4 (Wi-Fi)"
        case "iPad5,2":     return "iPad Mini 4 (Cellular)"
        case "iPad5,3":     return "iPad Air 2 (Wi-Fi)"
        case "iPad5,4":     return "iPad Air 2 (Cellular)"
        case "iPad6,3":     return "iPad Pro 9.7' (Wi-Fi)"
        case "iPad6,4":     return "iPad Pro 9.7' (Cellular)"
        case "iPad6,7":     return "iPad Pro 12.9' (Wi-Fi)"
        case "iPad6,8":     return "iPad Pro 12.9' (Cellular)"
        case "AppleTV2,1":  return "Apple TV 2G"
        case "AppleTV3,1":  return "Apple TV 3"
        case "AppleTV3,2":  return "Apple TV 3 (2013)"
        case "AppleTV5,3":  return "Apple TV 4"
        case "Watch1,1":    return "Apple Watch Series 1 (38mm, S1)"
        case "Watch1,2":    return "Apple Watch Series 1 (42mm, S1)"
        case "Watch2,6":    return "Apple Watch Series 1 (38mm, S1P)"
        case "Watch2,7":    return "Apple Watch Series 1 (42mm, S1P)"
        case "Watch2,3":    return "Apple Watch Series 2 (38mm, S2)"
        case "Watch2,4":    return "Apple Watch Series 2 (42mm, S2)"
        case "i386":        return "Simulator"
        case "x86_64":      return "Simulator"

        default:
            return ""
        }
    }
}

你可以在GitHub上查看GBDeviceInfo，也可以通过CocoaPods获得。它提供了简单的API来检测各种属性，支持所有最新的设备:

设备的家庭

[GBDeviceInfo deviceDetails]。family == GBDeviceFamilyiPhone;

设备模型

[GBDeviceInfo deviceDetails]。model == GBDeviceModeliPhone6。

欲了解更多，请参阅Readme。

更有用

#include <sys/types.h>
#include <sys/sysctl.h>

@interface UIDevice(Hardware)

- (NSString *) platform;

- (BOOL)hasRetinaDisplay;

- (BOOL)hasMultitasking;

- (BOOL)hasCamera;

@end

@implementation UIDevice(Hardware)

- (NSString *) platform{
    int mib[2];
size_t len;
char *machine;

mib[0] = CTL_HW;
mib[1] = HW_MACHINE;
sysctl(mib, 2, NULL, &len, NULL, 0);
machine = malloc(len);
sysctl(mib, 2, machine, &len, NULL, 0);

    NSString *platform = [NSString stringWithCString:machine encoding:NSASCIIStringEncoding];
    free(machine);
return platform;
}

- (BOOL)hasRetinaDisplay {
    NSString *platform = [self platform];
    BOOL ret = YES;
    if ([platform isEqualToString:@"iPhone1,1"]) {
        ret = NO;
    }
    else
        if ([platform isEqualToString:@"iPhone1,2"])    ret = NO;
    else 
        if ([platform isEqualToString:@"iPhone2,1"])    ret = NO;
    else 
        if ([platform isEqualToString:@"iPod1,1"])      ret = NO;
    else
        if ([platform isEqualToString:@"iPod2,1"])      ret = NO;
    else
        if ([platform isEqualToString:@"iPod3,1"])      ret = NO;
    return ret;
}

- (BOOL)hasMultitasking {
    if ([self respondsToSelector:@selector(isMultitaskingSupported)]) {
        return [self isMultitaskingSupported];
    }
    return NO;
}

- (BOOL)hasCamera {
   BOOL ret = NO;
   // check camera availability
   return ret;
}

@end

您可以读取属性

NSLog(@"platform %@, retita %@, multitasking %@", [[UIDevice currentDevice] platform], [[UIDevice currentDevice] hasRetinaDisplay] ? @"YES" : @"NO" , [[UIDevice currentDevice] hasMultitasking] ? @"YES" : @"NO");

NSString *deviceType = [[UIDevice currentDevice] systemName];

我可以保证，上述建议将适用于iOS 7及以上版本。我相信iOS 6也能运行。但我不确定。