feat: tommy tran lesson_4 function added in java and js (#141)

* feat:lesson_4 function added in java and js

* fix: added additional information to readme.md

Author: txtran224

lesson_04/tommytran/lesson_4.java

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+public class lesson_4 {
+
+    // Function to check if a number is prime
+    public static boolean isPrime(int n) {
+        if (n < 2) {
+            return false; // Numbers less than 2 are not prime
+        }
+        if (n == 2) {
+            return true; // 2 is the only even prime number
+        }
+        if (n % 2 == 0) {
+            return false; // Numbers divisible by 2 are not prime
+        }
+        // Loop that checks every odd number up to the square root of n
+        for (int i = 3; i <= Math.sqrt(n); i += 2) {
+            if (n % i == 0) {
+                return false; // n is divisible by i, so it's not prime
+            }
+        }
+        return true; // n is prime
+    }
+
+    public static void main(String[] args) {
+        // Declare integers in main method
+        int a = 1;
+        int b = 9;
+        int c = 17;
+
+        // Return string of whether or not int is a prime number
+        System.out.println("Is " + a + " a prime number? " + isPrime(a));
+        System.out.println("Is " + b + " a prime number? " + isPrime(b));
+        System.out.println("Is " + c + " a prime number? " + isPrime(c));
+    }
+}
+// code sourced from chat-gpt after converting my JS file.

lesson_04/tommytran/lesson_4.js

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+   
+    //declare integers in function: sample numbers
+    let a = 1;
+    let b = 9;
+    let c = 17;
+{    
+function Prime(n) {
+    if (n < 2) {
+        return false; // Numbers less than 2 are not prime
+    }
+    if (n === 2) {
+        return true; // 2 is the only even prime number
+    }
+    if (n % 2 === 0) {
+        return false; // numbers divisible by 2 are not prime
+    }
+    // loop that checks every odd number up until square root of n
+    for (let i = 3; i <= Math.sqrt(n);i +=2) {
+        if (n % i === 0) {
+            return false; // n is divisible by i, so it's not prime 
+        }
+    }
+    return true; // n is prime
+}
+//return string of whether or not int is a prime number
+console.log(`Is ${a} a prime number? ${Prime(a)}`);
+console.log(`Is ${b} a prime number? ${Prime(b)}`);
+console.log(`Is ${c} a prime number? ${Prime(c)}`);
+}

lesson_04/tommytran/readme.md

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+## Explanation
+
+
+First I declared 3 variables to use to test my function a,b, and c. I then assigned 3 integers to these variables to test this function. I created a function by the name of prime that contained an if else statement and a for loop. I then created several rules for the the if statement. The first rule determined whether the number was less than 2 then it was considered not a prime number. The second rule was that the number 2 would return true as it is the only even prime number. the third rule was that any number that was divided by 2 would not leave a remainder a 0. If none of those conditions were satisfied then a for loop would activate starting from the number 3. The loop would check all numbers starting at number #3 and must be less than or equal to the square root of (n). The loop would then increase integer by 2 to check every odd number between 3 and the square root. If any number that was determined (n) to be divisible by (i) then it was false and not a prime number. If there was no odd divisble numbers then the statement would return true. Afterwards I would test the function by inputting a console.log command in the terminal to print a string that determined whether or not the number in each variable was a prime number or not.
+
+
+### Similiarities and Differences
+
+
+1. **Syntax**: 
+   - to print messages in the console in javascript you would do console.log
+   - to print messages in the console in Java you would use the System.out.println command
+   - although they are different they ultimately perform the same action and the function's are built in a very similar order/pattern.
+
+2. ** Variables
+   - In javascript you can declare a variablle using let and achieve a more broader scope of defined objects whereas in Java you have to be more specific with the data type as an int,double,string,etc.
+
+3. ** Testing
+   - to run the java you would name the file with a .java at the end and type "java [filename.java]" to run the program
+   - to run the javascrip you would name the file with a .js at the end and type node [filename.js] to run the program