Question

Write a program that adds the numbers 1 through 5 into the numbers ArrayList and then prints out the first element in the list.

Answer 1

Answer:

Answer code is given below along with comments to explain each step

Explanation:

Method 1:

// size of the array numbers to store 1 to 5 integers

int Size = 5;  

// here we have initialized our array numbers, the type of array is integers and size is 5, right now it is empty.

ArrayList<Integer> numbers = new ArrayList<Integer>(Size);

// lets store values into the array numbers one by one

numbers.add(1)

numbers.add(2)

numbers.add(3)

numbers.add(4)

numbers.add(5)

// here we are finding the first element in the array numbers by get() function, the first element is at the 0th position

int firstElement = numbers.get(0);

// to print the first element in the array numbers

System.out.println(firstElement);  

Method 2:

int Size = 5;  

ArrayList<Integer> numbers = new ArrayList<Integer>(Size);

// here we are using a for loop instead of adding manually one by one to store the values from 1 to 5

for (int i = 0; i < Size; i++)  

{

// adding the values 1 to 5 into array numbers

  numbers.add(i);  

}

//here we are finding the first element in the array numbers

int firstElement = numbers.get(0);  

// to print the first element in the array

System.out.println(firstElement);