1.5 Arrays of Structures

It’s also possible to create arrays whose elements are structures. The technique is exactly the same as for creating arrays of the fundamental types. For example, to create an array of 100 inflatable structures, you could do the following:

inflatable gifts[100]; // array of 100 inflatable structures

This makes gifts an array of inflatables. Hence each element of the array, such as gifts[0] or gifts[99], is an inflatable object and can be used with the membership operator:

cin >> gifts[0].volume; // use volume member of first struct

cout << gifts[99].price << endl; // display price member of last struct

Keep in mind that gifts itself is an array, not a structure, so constructions such as gifts.price are not valid.

To initialize an array of structures, you combine the rule for initializing arrays (a brace-enclosed, comma-separated list of values for each element) with the rule for structures (a brace-enclosed, comma-separated list of values for each member). Because each element of the array is a structure, its value is represented by a structure initialization. Thus, you wind up with a brace-enclosed, comma-separated list of values, each of which itself is a brace-enclosed, comma-separated list of values:

inflatable guests[2] = { // initializing an array of structs

{“Bambi”, 0.5, 21.99}, // first structure in array

{“Godzilla”, 2000, 565.99} // next structure in array

};

Listing 3 shows a short example that uses an array of structures. Note that because guests is an array of inflatable, guest[0] is type inflatable, so you can use it with the dot opera-tor to access a member of the inflatable structure.

Listing 3

struct inflatable {

char name[20];

float volume;

double price;

};

void main() {

inflatable guests[2] = { // initializing an array of structs

{“Bambi”, 0.5, 21.99}, // first structure in array

{“Godzilla”, 2000, 565.99} // next structure in array

};

cout << “The guests “ << guests[0].name << “ and “ << guests[1].name << “\nhave a combined volume of “ << guests[0].volume + guests[1].volume << “ cubic feet.\n”;

}

Here is the output of the program in Listing 3:

The guests Bambi and Godzilla

have a combined volume of 2000.5 cubic feet.

2. Lab Overview

2.1. Read the theory and try Control Exercises.

2.2. Develop the algorithm flowchart to create input data and handle structures array according to individual case from the Table below.

2.3. Write the program code according to the developed algorithm. Dynamic variables, pointers, user-defined functions should be used.

2.4. Debug the program, run it and make screenshots.

2.5. Prepare the Lab Report according to the required structure.

#	Structures array	Operation on array
	Books	Find a book with a minimum number of pages
	Vegetables	Find vegetables with red color
	Computers	Output a configuration of the most expensive computer
	Films	Find a film with a highest budget
	Shoes	Output shoes with a price more than average one
	Cell phones	Output Nokia cell phones
	Students	Calculate the group average rating
	Laptops	Output laptops with a screen diagonal more than 15 inches
	Fruits	Output fruits with weight less than 200g
	Shirts	Find a shirt with a lowest price
	Bags	Find a bag with a highest number of pockets
	Soundtracks	Output soundtracks of the film “Transformers”
	Drinks	Output non-alcoholic drinks
	Pens	Output black pens with a price more than $100
	Workers	Find a worker with a highest salary
	Cars	Output cars of 2012 year
	Songs	Output songs with a rating bellow the indicated one
	Soft	Output freeware soft
	Animals	Calculate the total weight of all animals in the database
	Countries	Output countries with a population more than the population in Ukraine
	Soccer Teams	Output teams which won Champion League more than 3 times
	Tanks	Output middle weight tanks
	Motorcycles	Output motorcycles with engine volume more than 50 sm3
	Rock groups	Output rock groups from Ukraine
	Cosmetics	Output goods from Avon