An array is a simple data structure used to store a collection of data in a contiguous block of memory. Each element in the collection is accessed using an index, and the elements are easy to find because they're stored sequentially in memory.
Because the collection of elements in an array is stored as a big block of data, we typically use arrays when we know exactly how many pieces of data we're going to have. For example, you might use an array to store a list of student ID numbers, or the names of state capitals. To create an array of integers named that can hold four integer values, you would write the following code:
int myArray = new int;
This sets aside a block of memory that's capable of storing integers. Each integer storage cell is assigned a unique index ranging from to one less than the size of the array, and each cell initially contains a . In the case of , we can store integers at indices , , , and . Let's say we wanted the last cell to store the number ; to do this, we write:
myArray = 12;
Similarly, we can print the contents of the last cell with the following code:
The code above prints the value stored at index of , which is (the value we previously stored there). It's important to note that while Java initializes each cell of an array of integers with a , not all languages do this.
The code in your editor does the following:
Reads an integer from stdin and saves it to a variable, , denoting some number of integers.
Reads integers corresponding to from stdin and saves each integer to a variable, .
Attempts to print each element of an array of integers named .
Write the following code in the unlocked portion of your editor:
Create an array, , capable of holding integers.
Modify the code in the loop so that it saves each sequential value to its corresponding location in the array. For example, the first value must be stored in , the second value must be stored in , and so on.
The first line contains a single integer, , denoting the size of the array.
Each line of the subsequent lines contains a single integer denoting the value of element .
You are not responsible for printing any output to stdout. Locked code in the editor loops through array and prints each sequential element on a new line.
When we save each integer to its corresponding index in , we get . The locked code prints each array element on a new line from left to right.