feat: Ezra's lesson 4 assignment (#150)

* feat: Ezra's lesson 4 assignment

* fix: Made minor changes.

* fix: Deleted PrimeNumber.java file

* feat: Ezra's lesson 4 assignment

* fix: Made minor changes.

* fix: Fixed the indentation and removed the priod.

* fix: Fixed the indentation and removed the priod.

* Delete PrimeNumber.java

---------

Co-authored-by: Ezra Nyabuti <[email protected]>

Author: enyabuti

lesson_04/ezra4/PrimeNumber.java

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+import java.util.Scanner;               // This package for reading input
+
+public class PrimeNumber {              // This is the class name
+
+    public static boolean isPrime(int num) {            // Function to check if number is prime or not.
+        if (num <= 1) return false;                     // If number is less than or equal to 1, it is not prime.
+        for (int i = 2; i <= Math.sqrt(num); i++) {     // Loop to check if number is prime or not.
+            if (num % i == 0) return false;             
+        }
+        return true;
+    }
+
+    public static void main(String[] args) {            // This is the main function
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Enter a number:");
+        int num = scanner.nextInt();
+
+        if (isPrime(num)) {
+            System.out.println(num + " is prime.");
+        } else {
+            System.out.println(num + " is not prime.");
+        }
+    }
+}

lesson_04/ezra4/README.md

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+## Python Implementation
+
+```python
+def prime_num(num):
+    if num <= 1:
+        return False
+    for i in range(2, num): 
+        if num % i == 0:
+            return False
+    return True
+```
+
+## Java Implementation
+
+
+```java
+public static void main(String[] args) { 
+    Scanner scanner = new Scanner(System.in);
+    System.out.print("Enter a number:");
+    int num = scanner.nextInt();
+
+    if (isPrime(num)) {
+        System.out.println(num + " is prime.");
+    }
+    else {
+        System.out.println(num + " is not prime.");
+    }
+}
+```
+
+
+### Python Explanations
+ When we look at the python implementation, we define a function and give it and attribute `(num)`. We introduce the `if` statement and `for` loop to iterate over the funtion and check if it matches the requirements. We later propmt user to input a number and the code will verify if all the requirements are met to qualify it as a prime number. 
+
+
+
+### Java Explanation
+
+In java we have a different approach. Unlike python we define our class using `(public class)` named `PrimeNumber`.Both Python and java use conditional statement loops to iterate over the functions. The function is later iterated on the main class
+
+
+
+### Difference
+
+1. Python uses `def` keyword to define a funtion while Java uses, `public static boolean` to define a function.
+
+2. Java uses `System.out.print()` to print out the statement and python uses `print()` to print statement.
+
+
+3. I notice i have to import `java.util.Scanner` to prompt user to input a number while python you only need to use, `input()`

lesson_04/ezra4/numbers.py

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+
+# Function to check if a number is prime
+
+def prime_num(num):  # This is function to check if a number is prime
+    if num <= 1:  # This will help check if number is less than or equal to 1
+        return False
+    for i in range(2, num):  # This will help check if number is divisible by any number between 2 and the number itself
+        if num % i == 0:
+            return False
+    return True
+
+
+# Ask user for a number and check if it is prime
+number = int(input("Enter a number: "))
+if prime_num(number):
+    print(f"{number} is a prime number.")
+else:
+    print(f"{number} is not a prime number.")