Learning Java for Python Programmers/

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Arrays, Lists, Maps, and Loops

Arrays, Lists, Maps, and Loops

Learn the distinction between Python’s mutable lists and Java’s fixed-size arrays, emphasizing their flexibility and constraints.

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Arrays

An array is a type of data structure that holds a number of elements of the same type sequentially in adjacent memory addresses. It provides a convenient way to access and manipulate multiple values of the same type as a single entity.

In Python, arrays are implemented using lists, which are powerful objects overflowing with useful properties. Lists in Python are regarded as mutable arrays that can grow or shrink in real-time when new elements are added or removed.

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# Creating an array (list) in Python
my_list = [1, 2, 3, 4, 5]
# Accessing elements of the array
print("First element:", my_list[0])   
# Modifying elements of the array
my_list[0] = 10
print("Modified array:", my_list)

In Java, arrays are fixed-size data structures where the size needs to be specified at the time of declaration. Unlike Python lists, Java arrays can only hold elements of the same type.

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// Import the Arrays class from java.util
import java.util.Arrays;
class MyJavaApp {
  public static void main( String args[] ) {
    // Creating an array in Java
    int[] myArray = {1, 2, 3, 4, 5};
    // Accessing elements of the array
    System.out.println("First element: " + myArray[0]);  
    // Modifying elements of the array
    myArray[0] = 10;
    System.out.println("Modified array: " + Arrays.toString(myArray)); 
  }
}

Arrays in Python and Java are designed to store and perform an operation on a set of objects in a manner that is both effective and efficient. But, there are divergences in their type of implementation and purposes. Python lists have been equipped with more flexibility and dynamic resizing features, however, Java arrays require that you predetermine the size and every element in them should be the same type.

Homogeneous vs. heterogeneous data

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