数组和字符串是否有值(是否为空) 判断
- if (array != nil && ![array isKindOfClass:[NSNull class]] && array.count != 0)
2 判断字符串
- (BOOL) isBlankString:(NSString *)string { if (string == nil || string == NULL) { return YES; } if ([string isKindOfClass:[NSNull class]]) { return YES; } if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] length]==0) { return YES; } return NO; }