iOS determines the current device type

The code is as follows:

+ (nsstring*) devicestring

{

// need to #import "Sys/utsname.h"

struct utsname SystemInfo;

uname (&systeminfo);

nsstring *devicestring = [nsstring stringwithcstring: SystemInfo. Machine encoding:nsutf8stringencoding];

if    ([devicestring isequaltostring:@ "iphone1,1"]) return @ "IPhone 1G";

if    ([devicestring isequaltostring:@ "iphone1,2"]) return @ "IPhone 3G";

if    ([devicestring isequaltostring:@ "iphone2,1"]) return @ "IPhone 3GS";

if    ([devicestring isequaltostring:@ "iphone3,1"]) return @ "IPhone 4";

if ([devicestring isequaltostring:@ "iphone3,2"]) return @ "Verizon iPhone 4";

if    ([devicestring isequaltostring:@ "iphone4,1"]) return @ "IPhone 4S";

if    ([devicestring isequaltostring:@ "iphone5,2"]) return @ "IPhone 5";

if    ([devicestring isequaltostring:@ "iphone5,3"]) return @ "IPhone 5C";

if    ([devicestring isequaltostring:@ "iphone5,4"]) return @ "IPhone 5C";

if    ([devicestring isequaltostring:@ "iphone6,2"]) return @ "IPhone 5S";

if      ([devicestring isequaltostring:@ "ipod1,1"]) return @ "IPod Touch 1G";

if      ([devicestring isequaltostring:@ "ipod2,1"]) return @ "IPod Touch 2G";

if      ([devicestring isequaltostring:@ "ipod3,1"]) return @ "IPod Touch 3G";

if      ([devicestring isequaltostring:@ "ipod4,1"]) return @ "IPod Touch 4G";

if      ([devicestring isequaltostring:@ "ipad1,1"]) return @ "IPad";

if      ([devicestring isequaltostring:@ "ipad2,1"]) return @ "IPad 2 (WiFi)";

if      ([devicestring isequaltostring:@ "ipad2,2"]) return @ "IPad 2 (GSM)";

if      ([devicestring isequaltostring:@ "ipad2,3"]) return @ "IPad 2 (CDMA)";

if      ([devicestring isequaltostring:@ "ipad2,5"]) return @ "IPad Mini";

if         ([devicestring isequaltostring:@ "i386"]) return @ "Simulator";

if       ([devicestring isequaltostring:@ "x86_64"]) return @ "Simulator";

NSLog(@ "Note:unknown device type:%@", devicestring);

return devicestring;

}