IOS判断是否为数字

 - (BOOL)isPureInt:(NSString *)string{
 NSScanner* scan = [NSScanner scannerWithString:string];
 int val;
 return [scan scanInt:&val] && [scan isAtEnd];
 }

判断是否为浮点形： 

 - (BOOL)isPureFloat:(NSString *)string{
 NSScanner* scan = [NSScanner scannerWithString:string];
 float val;
 return [scan scanFloat:&val] && [scan isAtEnd];
 }