1-D Arrays

[falonsade]

Good evening,

I apologize for what will seem like a simple question, however I'm having issues wrapping my head around/conceptualizing 1-D arrays. I understand arrays a more efficient, quicker way to store and call a set of data, but where would one use an array in real-life? The textbook we're using likes to use "sales by region" and similar examples as reference, but they're difficult topics to conceptualize (I'm an artist and this isn't my strong suit, but I'm trying!)

Also, when initializing a six-element double array like below, does it have to be initialized with 0.0 or can you initialize to nothing (just { })?

double sales [6] = {0.0}

I appreciate your patience and any your time. This is very difficult for me and I'm thankful for even the simplest of explanations.

[MiiNiPaa]

You will need arrays when you deal with large amount of similar data. For example: grades of students, hours worked per week for entire year, info on all cars in shop and others.

[giblit]

A 1-D (or a normal) array is simply a list of items or the x location of things
imagine this

a list of foods
apple
orange
banana
grape

you could turn that into an "array" in c++ by multiple ways.

The most simple way would be this
string array[4] = {"apple", "orange", "banana", "grape"};

there are several other ways.

Key things to keep in mind.
1) If you know how large the array will be all the time you can set a size of the array like this string array[SIZE]; you can use other variable types also.

2) If you know the size of the array, and the values for the array you can set the size, and values. string array[SIZE] = {"VALUES", "VALUES"};

3) You wish to dynamically create the array and have a starting size
vector<string> array(SIZE);

4) You wish to dynamically create the array and have a starting size/starting values

 vector<string> array(SIZE);
array[POSITION] = "VALUE";
array[POSITION] = "VALUE";

5) If you wish to add more values to the starting array(or remove)

vector<string> array;
array.push_back("hello");
array.push_back("world");
array.pop_back(); //remove last item
array.pop_back();

To get items from array think of this position left to right 0 -> 3 would mean the array is a size of 4;
an example of how to get values

double sales[4] = {1.23, 2.13, 3.21, 4.59};
for(int i = 0; i<4; i++) cout << "sales[" << i << "]: " << sales[i] << endl;
//or you can do this
vector<double> array(2);
    array[0] = (1.23);
    array[1] = (2.13);
    array.push_back(3.21);
    array.push_back(4.59);
    for(int i = 0; i<array.size(); i++) cout << "array[" << i << "]: " << array[i] << endl;

and your question about initializing to nothing you would put

double sales[6];
//or
double sales[6] = {0,0,0,0,0,0}; //this though would initalize then set all values equal to 0 

and not

double sales[6] = {}
//or
double sales[6] = {0.0}; // this would only set position 0 equal to 0 and 
//you probably get an error because you did not give a value for the other
// 5 positions. 

[falonsade]

Thank you both very much! giblit, I greatly appreciate you laying out all out there for me. The textbook we're using has some good information, but it's spread in such a way that it's difficult for me to tie it all together. I am thankful for your time!

[MiiNiPaa]

giblit
From OP post Ican conclude that he is still struggling with basics, so do not dump all of this info he will not ge most of on him.

And do not provide false information: you can use

double sales[6] = {};//and
double sales[6] = {0.0};

just fine: all omitted values vill be value initializated (i.e. set to zero here). (Standard 8.5.1.7)

[giblit]

ah I see I don't use preset arrays I use dynamic ones