The following issues were found

lectures/7-methods/code/src/com/kunal/Shadowing.java
4 issues
System.out.println is used
Design

Line: 6 

              public class Shadowing {
    static int x = 90; // this will be shadowed at line 8
    public static void main(String[] args) {
        System.out.println(x); // 90
        int x; // the class variable at line 4 is shadowed by this
//        System.out.println(x); // scope will begin when value is initialised
        x = 40;
        System.out.println(x); // 40
        fun();

Reported by PMD.

System.out.println is used
Design

Line: 10 

                      int x; // the class variable at line 4 is shadowed by this
//        System.out.println(x); // scope will begin when value is initialised
        x = 40;
        System.out.println(x); // 40
        fun();
    }

    static void fun() {
        System.out.println(x);

Reported by PMD.

System.out.println is used
Design

Line: 15 

                  }

    static void fun() {
        System.out.println(x);
    }
}

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 3 

              package com.kunal;

public class Shadowing {
    static int x = 90; // this will be shadowed at line 8
    public static void main(String[] args) {
        System.out.println(x); // 90
        int x; // the class variable at line 4 is shadowed by this
//        System.out.println(x); // scope will begin when value is initialised
        x = 40;

Reported by PMD.

lectures/7-methods/code/src/com/kunal/StringExample.java
4 issues
System.out.print is used
Design

Line: 12 

              //        System.out.println(message);

        Scanner in  = new Scanner(System.in);
        System.out.print("Enter your name: ");
        String naam = in.next();
        String personalised = myGreet(naam);
        System.out.println(personalised);
    }

Reported by PMD.

System.out.println is used
Design

Line: 15 

                      System.out.print("Enter your name: ");
        String naam = in.next();
        String personalised = myGreet(naam);
        System.out.println(personalised);
    }

    static String myGreet(String name) {
        String message = "Hello " + name;
        return message;

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Scanner;

public class StringExample {

    public static void main(String[] args) {
//        String message = greet();
//        System.out.println(message);

Reported by PMD.

Ensure that resources like this Scanner object are closed after use
Error

Line: 11 

              //        String message = greet();
//        System.out.println(message);

        Scanner in  = new Scanner(System.in);
        System.out.print("Enter your name: ");
        String naam = in.next();
        String personalised = myGreet(naam);
        System.out.println(personalised);
    }

Reported by PMD.

lectures/5-first-java-program/first-idea-program/src/com/kunal/Temperature.java
4 issues
System.out.print is used
Design

Line: 8 

              public class Temperature {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Please enter temp in C: ");
        float tempC = in.nextFloat();
        float tempF = (tempC * 9/5) + 32;
        System.out.println(tempF);
    }
}

Reported by PMD.

System.out.println is used
Design

Line: 11 

                      System.out.print("Please enter temp in C: ");
        float tempC = in.nextFloat();
        float tempF = (tempC * 9/5) + 32;
        System.out.println(tempF);
    }
}

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Scanner;

public class Temperature {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Please enter temp in C: ");
        float tempC = in.nextFloat();
        float tempF = (tempC * 9/5) + 32;

Reported by PMD.

Ensure that resources like this Scanner object are closed after use
Error

Line: 7 

              
public class Temperature {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Please enter temp in C: ");
        float tempC = in.nextFloat();
        float tempF = (tempC * 9/5) + 32;
        System.out.println(tempF);
    }

Reported by PMD.

lectures/10-binary search/code/src/com/kunal/InfiniteArray.java
4 issues
System.out.println is used
Design

Line: 8 

                      int[] arr = {3, 5, 7, 9, 10, 90,
                100, 130, 140, 160, 170};
        int target = 10;
        System.out.println(ans(arr, target));
    }
    static int ans(int[] arr, int target) {
        // first find the range
        // first start with a box of size 2
        int start = 0;

Reported by PMD.

Avoid reassigning parameters such as 'start'
Design

Line: 27 

                      return binarySearch(arr, target, start, end);

    }
    static int binarySearch(int[] arr, int target, int start, int end) {
        while(start <= end) {
            // find the middle element
//            int mid = (start + end) / 2; // might be possible that (start + end) exceeds the range of int in java
            int mid = start + (end - start) / 2;

Reported by PMD.

Avoid reassigning parameters such as 'end'
Design

Line: 27 

                      return binarySearch(arr, target, start, end);

    }
    static int binarySearch(int[] arr, int target, int start, int end) {
        while(start <= end) {
            // find the middle element
//            int mid = (start + end) / 2; // might be possible that (start + end) exceeds the range of int in java
            int mid = start + (end - start) / 2;

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 3 

              package com.kunal;
// https://www.geeksforgeeks.org/find-position-element-sorted-array-infinite-numbers/
public class InfiniteArray {
    public static void main(String[] args) {
        int[] arr = {3, 5, 7, 9, 10, 90,
                100, 130, 140, 160, 170};
        int target = 10;
        System.out.println(ans(arr, target));
    }

Reported by PMD.

lectures/7-methods/code/src/com/kunal/VarArgs.java
4 issues
System.out.println is used
Design

Line: 13 

                  }

    static void demo(int ...v) {
        System.out.println(Arrays.toString(v));
    }

    static void demo(String ...v) {
        System.out.println(Arrays.toString(v));
    }

Reported by PMD.

System.out.println is used
Design

Line: 17 

                  }

    static void demo(String ...v) {
        System.out.println(Arrays.toString(v));
    }

    static void multiple(int a, int b, String ...v) {

    }

Reported by PMD.

System.out.println is used
Design

Line: 25 

                  }

    static void fun(int ...v) {
        System.out.println(Arrays.toString(v));
    }
}

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Arrays;

public class VarArgs {
    public static void main(String[] args) {
//        fun();
//        multiple(2, 3, "Kunal", "Rahul", "dvytsbhusc");
//        demo();
    }

Reported by PMD.

lectures/5-first-java-program/first-idea-program/src/com/kunal/Inputs.java
4 issues
All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Scanner;

public class Inputs {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
//        System.out.print("Please enter some input: ");
//        int rollno = input.nextInt();
//        System.out.println("Your roll number is " + rollno);

Reported by PMD.

Ensure that resources like this Scanner object are closed after use
Error

Line: 7 

              
public class Inputs {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
//        System.out.print("Please enter some input: ");
//        int rollno = input.nextInt();
//        System.out.println("Your roll number is " + rollno);

//        String name = input.next();

Reported by PMD.

Avoid unused local variables such as 'input'.
Design

Line: 7 

              
public class Inputs {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
//        System.out.print("Please enter some input: ");
//        int rollno = input.nextInt();
//        System.out.println("Your roll number is " + rollno);

//        String name = input.next();

Reported by PMD.

Found 'DU'-anomaly for variable 'input' (lines '7'-'17').
Error

Line: 7 

              
public class Inputs {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
//        System.out.print("Please enter some input: ");
//        int rollno = input.nextInt();
//        System.out.println("Your roll number is " + rollno);

//        String name = input.next();

Reported by PMD.

lectures/8-arrays/code/src/com/kunal/ColNoFixed.java
4 issues
System.out.print is used
Design

Line: 13 

              
        for (int row = 0; row < arr.length; row++) {
            for (int col = 0; col < arr[row].length; col++) {
                System.out.print(arr[row][col] + " ");
            }
            System.out.println();
        }
    }
}

Reported by PMD.

System.out.println is used
Design

Line: 15 

                          for (int col = 0; col < arr[row].length; col++) {
                System.out.print(arr[row][col] + " ");
            }
            System.out.println();
        }
    }
}

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 3 

              package com.kunal;

public class ColNoFixed {
    public static void main(String[] args) {
        int[][] arr = {
                {1, 2, 3, 4},
                {5, 6},
                {7, 8, 9}
        };

Reported by PMD.

This for loop can be replaced by a foreach loop
Design

Line: 11 

                              {7, 8, 9}
        };

        for (int row = 0; row < arr.length; row++) {
            for (int col = 0; col < arr[row].length; col++) {
                System.out.print(arr[row][col] + " ");
            }
            System.out.println();
        }

Reported by PMD.

lectures/5-first-java-program/first-idea-program/src/com/kunal/Sum.java
3 issues
System.out.println is used
Design

Line: 13 

              
        float sum = num1 + num2;

        System.out.println("Sum = " + sum);
    }
}

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Scanner;

public class Sum {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        float num1 = input.nextFloat();
        float num2 = input.nextFloat();

Reported by PMD.

Ensure that resources like this Scanner object are closed after use
Error

Line: 7 

              
public class Sum {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        float num1 = input.nextFloat();
        float num2 = input.nextFloat();

        float sum = num1 + num2;

Reported by PMD.

lectures/8-arrays/code/src/com/kunal/Max.java
3 issues
System.out.println is used
Design

Line: 6 

              public class Max {
    public static void main(String[] args) {
        int[] arr = {1, 3, 2, 9, 18};
        System.out.println(maxRange(arr, 1, 3));
    }

    // work on edge cases here, like array being null
    static int maxRange(int[] arr, int start, int end) {

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 3 

              package com.kunal;

public class Max {
    public static void main(String[] args) {
        int[] arr = {1, 3, 2, 9, 18};
        System.out.println(maxRange(arr, 1, 3));
    }

    // work on edge cases here, like array being null

Reported by PMD.

Consider using varargs for methods or constructors which take an array the last parameter.
Design

Line: 29 

                      return maxVal;
    }

    static int max(int[] arr) {
        if (arr.length == 0) {
            return -1;
        }
        int maxVal = arr[0];
        for (int i = 1; i < arr.length; i++) {

Reported by PMD.

lectures/8-arrays/code/src/com/kunal/Swap.java
3 issues
System.out.println is used
Design

Line: 10 

                      int[] arr = {1, 3, 23, 9, 18, 56};
//        swap(arr, 0, 4);
        reverse(arr);
        System.out.println(Arrays.toString(arr));
    }

    static void reverse(int[] arr) {
        int start = 0;
        int end = arr.length-1;

Reported by PMD.

All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
Design

Line: 5 

              
import java.util.Arrays;

public class Swap {
    public static void main(String[] args) {
        int[] arr = {1, 3, 23, 9, 18, 56};
//        swap(arr, 0, 4);
        reverse(arr);
        System.out.println(Arrays.toString(arr));

Reported by PMD.

Consider using varargs for methods or constructors which take an array the last parameter.
Design

Line: 13 

                      System.out.println(Arrays.toString(arr));
    }

    static void reverse(int[] arr) {
        int start = 0;
        int end = arr.length-1;

        while (start < end) {
            // swap

Reported by PMD.