# The Unordered Array Abstract Data Type¶

The structure of an unordered array, as described above, is a collection of items where each item holds a relative position with respect to the others. Some possible unordered array operations are given below.

• int list[100] creates a new list that is a size of 100, and stores elements of integer data.

• front() accesses first element. Returns a reference to the first element in the array container.

• back() accesses last element. Returns a reference to the last element in the array container.

• empty() tests whether array is empty, and returns a boolean value showing whether the array is empty or not.

• size() returns size (the number of elements) in the array.

• fill(val) Sets val as the value for all the elements in the array object.

# Vectors¶

Vectors are more similar to lists in Python than arrays, in a way that they have dynamic size. Some operations with vectors are given below:

• #include <vector>; imports the vector library to be used

• vector<int> integerList; declares integerList as a vector, and its elements to be a type of int.

• vector<string> stringList; declares stringList as a vector, and its elements to be a type of string.

• clear() deletes all the items in the vector.

• erase(pos) deletes the item at a defined position.

• insert(pos, elem) inserts the copy of elem into a pos position in the vector.

• size() returns the size (the number of items) of the vector.

More found at http://www.cplusplus.com/reference/vector/vector/