可变数组 元素不能为空

NSArray *arr=@[model.account,model.rname];

NSArray *arr1=@[model.name,model.birthday,model.age,model.idNo,model.address];

NSArray *arr2=@[model.account,model.wcode,model.qcode];

NSArray *arr3=@[model.interests,model.sdasd];

_infoArray = [[NSMutableArray alloc]initWithObjects:@""，arr,arr1,arr2,arr3,nil]; 写法是错误的指针地址会报错