判断是否为整形：

- (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];

}