Making an array for a class

**sbook** · 05-26-2005

I'm just learning C++, and I've been given a project to make a class Person with 6 different parts to it. Then, I have to make an array of 5 people initializing each part for each person.

I wrote the class, but I don't know how to initialize the array of people.

Do I first have to declare:

Person P1, P2, P3, P4, P5, P6; (with parameters)

and then how do I declare the array?
Do I have to write Person first again or do I make it a certain data type. And does the name of the array have to be Person or different from person?

Thanks for any help

**jinhao** · 05-26-2005

Code:

class X
{
public:
    X(int, const char*){}
};

int main()
{
    X x[6]={X(1,"A"), X(2,"B"), X(3,"C"), X(4,"D"), X(5,"E"), X(6,"F")};
}

**sbook** · 05-26-2005

Thanks for the help

**sbook** · 05-26-2005

I'm having more problems. I made a class Person and each Person takes 6 parameters. Now, I'm supposed to make an array of 5 people. Can anyone tell me what is wrong with the code below? I really have not idea how to define this array, so I just tried to come up with something out of a book.

Thanks for any help

I attached my main file

I'm getting errors like:

left of '.Person' must have class/struct/union type
syntax error : identifier 'Person'
subscript requires array or pointer type

**sbook** · 05-26-2005

Sorry, I don't know if anyone can read my attached file above. It's:

Code:

Person P1 = new Person ("1a", "1b", "1c", "1d", "1e", "1f");
    Person P2 = new Person ("2a", "2b", "2c", "2d", "2e", "2f");
    Person P3 = new Person ("3a", "3b", "3c", "3d", "3e", "3f");
    Person P4 = new Person ("4a", "4b", "4c", "4d", "4e", "4f");
    Person P5 = new Person ("5a", "5b", "5c", "5d", "5e", "5f");
 
    Person People[SIZE] = {P1, P2, P3, P4, P5};

[CODE]

**elad** · 05-26-2005

Person P1 = new Person ("1a", "1b", "1c", "1d", "1e", "1f");

the new operator will return an address that will be assigned to P1. Therefore P1 needs to be a pointer to type Person. The Person class also needs a non-default constructor that takes 6 strings in order for this to work.
If P1 is a pointer to type Person, then the following is an error. People would need to be an array of pointers to type Person.

Code:

Person People[SIZE] = {P1, P2, P3, P4, P5};

I think you will be better off not trying to initalize 5 Persons with six attributes, but to assign six attributes to 5 Persons.

If you must initialize, try the template jinhoa provided:

Code:

//in Person class declare a constructor that describe the attributes
//here each attribute is a string
Person (string, string, string, string, string, string);
 
//declare array of five Persons and initialize each Person
Person People[5] = {Person("1a", "1b", "1c", "1d", "1e", "1f"),
							Person("2a", "2b", etc.

I usually use the assignment approach so I can't swear by the initialization syntax, though it would be easy enough to try if I had a compiler handy.

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