Could someone help me, by telling me what this actually does?

[kevindav1]

I always see this codefor (unsigned int i = 0; i <inventory.size(); ++i) As i'm learning i'm confused what this does and how it works this bit particularly. i <inventory.size(); ++i) could someone explain in a little bit of detail? Here is all the code so far if needed. Thanks in advanced :)

(Not finished)

#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main()
{
    vector<string> inventory;
    inventory.push_back("sword");
    inventory.push_back("armor");
    inventory.push_back("shield");
    
    cout << "You have " << inventory.size() << " items\n";
    
    cout << "\nYour items:\n";
    for (unsigned int i = 0; i <inventory.size(); ++i)
    {
        cout << inventory[i] << endl;
    }
}

[kooth]

This is a typical "for" loop. There are three expressions to a "for" loop, the first two are delimited by a semi-colon (;) :

First, You have an expression that initializes the loop -- this is usually one variable -- I like to think of it as the controlling variable;

Second, You have a test, which is made before each iteration of the loop;

Third, You have an expression that usually is an incrementation of the initializing variable.

So in the example you posted, you have:

for( unisgned int i = 0; i < inventory.size(); i++ )

The first expression is "unisigned int i = 0". This is the initialization expression, and "i" is the controlling variable.

For the second expression you have " i < inventory.size();". This is the test expression. It is executed before anything within the loop.

Finally, the third expression is "i++". This gets after anything within the loop.

So this loop is going through all of the items in the inventory vector and printing each member on its own line.

[metulburr]

inventory is a vector. A vector can grow and shrink in size. vector.push_back() appends its arguments to the vector. The for loop, header line is like any other for loop in c++, where instead of the number. size() is a member function of vectors, in which returns the integer value of the size. So if the size is 3, it would be:
i <inventory.size();
converts to:
i < 3;

and basic for loop structure is:
for(counting variable; condition; increment)

So i starts at 0, the loops progresses to inventory's size(), which is 3, which completes teh for loops condition exiting the loop. The ++i increments i on each loop. The unsigned keyword is extra to indicate that i will never be negative.

[kevindav1]

Thanks people it really helped!