Terms you'll find helpful in completing today's challenge are outlined below, along with sample Java code (where appropriate).
Data Structures
A way of organizing data that enables efficient storage, retrieval, and use.
Arrays
A type of data structure that stores elements of the same type (generally). It's important to note that you'll often see arrays referred to as in documentation, but the variable names you use when coding should be descriptive and begin with lowercase letters.
You can think of an array, , of size as a contiguous block of cells sequentially indexed from to which serve as containers for elements of the array's declared data type. To store an element, , in some index of array , use the syntax A[i] and treat it as you would any other variable (i.e., A[i] = value;). For example, the following code:
// the number of elements we want to hold
final int _arraySize = 4;
// our array declaration
String[] stringArray = new String[_arraySize];
for(int i = 0; i < _arraySize; i++) {
// assign value to index i
stringArray[i] = "This is stored in index " + i;
// print value saved in index i
System.out.println(stringArray[i]);
}
saves and then prints the values listed below in their respective indices of :
This is stored in index 0
This is stored in index 1
This is stored in index 2
This is stored in index 3
Most languages also have a method, attribute, or member that allows you to retrieve the size of an array. In Java, arrays have a attribute; in other words, you can get the length of some array, arrayName, by using the arrayName.length syntax.
Note: The final keyword used in the code above is a means of protecting the variable's value by locking it to its initialized value. Any attempt to reassign (overwrite) the value of a final variable will generate an error.
Note on Arrays in C++
If you want to create an array whose size is unknown at compile time (i.e., being read as input), you need to create a pointer to whatever data type you'll be declaring your array as (e.g., char, int, double, etc.). Then you must use the new operator to set aside the space you need for your array. The example below shows how to create an array of type DataType and unknown size n that is read from stdin.
// array size
int n;
cin >> n;
// create array of unknown size n
DataType* arrayName = new DataType[n];