declare arraylist java code example

Example 1: how to define an arraylist in java

ArrayList<Integer> integerArray = new ArrayList<Integer>();
ArrayList<String> integerArray = new ArrayList<String>();
ArrayList<Double> integerArray = new ArrayList<Double>();
//... keep replacing what is inside the <> with the appropriate
//data type

Example 2: how to declare an array in java

An array is an ordered collection of elements of the same type, identified by a pair of square brackets []. 
 
 To use an array, you need to:
1. Declare the array with a name and a type. Use a plural name for array, e.g., marks, rows, numbers. All elements of the array belong to the same type.
2. Allocate the array using new operator, or through initialization, e.g.
  
  int[] marks;  // Declare an int array named marks
              // marks contains a special value called null.
int marks[];  // Same as above, but the above syntax recommended
marks = new int[5];   // Allocate 5 elements via the "new" operator
// Declare and allocate a 20-element array in one statement via "new" operator
int[] factors = new int[20];
// Declare, allocate a 6-element array thru initialization
int[] numbers = {11, 22, 33, 44, 55, 66}; // size of array deduced from the number of items

Example 3: how to make an arraylist java

ArrayList<Integer> integerArray = new ArrayList<Integer>();
ArrayList<String> stringArray = new ArrayList<String>();
ArrayList<Double> doubleArray = new ArrayList<Double>();
//... keep replacing what is inside the <> with the appropriate
//data type

Example 4: how to make a new arraylist java

ArrayList<Type> name = new ArrayList<Type>();

Example 5: declare bufferedreader java

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

Example 6: java how to create arraylist

import java.util.ArrayList;
//create ArrayList
ArrayList<String> arrayList = new ArrayList<String>();