PrimeNumberDemo added

Author: CMPundhir

InfiniteLoopDemo.java

@@ -0,0 +1,10 @@
+class InfiniteLoopDemo{
+	public static void main(String[] args){
+		//for(;;){
+		//	System.out.println("i am infinite loop");
+		//}
+		while(true){
+			System.out.println("i am infinite loop");
+		}
+	}
+}

MethodsDemo.java

@@ -0,0 +1,37 @@
+//why we use methods?
+//1.code reusability
+//2.makes our program easy to write and understand with clean code 
+class MethodsDemo{
+	public static void show(){
+		System.out.println("Bakwaasaassssss");
+	}
+	public static int add(){
+		return 2+5;
+	}
+	public static int mul(int a,int b){
+		return a*b;
+	}
+	//arr[]
+	public static int average(int[] arr){
+		int numOfSub = arr.length;
+		int totalMarks = 0;
+		for(int marks : arr){
+			totalMarks = totalMarks + marks;
+		}
+		int avg = totalMarks/numOfSub;
+		return avg;
+	}
+	public static void main(String[] args){
+		show();
+		int a = add();
+		System.out.println(a);
+		int b = mul(7,2);
+		System.out.println(b);
+		int[] arr = {100,89,98,90,32};
+		int avg = average(arr);
+		System.out.println(avg);
+		int[] arr2 = {0,5,7,12,16};
+		int avg2 = average(arr2);
+		System.out.println(avg2);
+	}
+}

PrimeNumberDemo.java

@@ -0,0 +1,25 @@
+import java.util.Scanner;
+class PrimeNumberDemo{
+	//Q. what is a Prime Number?
+	//Ans. a number that is divisible only by itself and 1 (e.g. 2, 3, 5, 7, 11).
+	
+	public static boolean isPrime(int num){
+		for(int i=2;i<num;i++){
+			if(num%i==0){
+				return false;
+			}
+		}
+		return true;
+	}
+	
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter a number : ");
+		int a = sc.nextInt();
+		if(isPrime(a)){
+			System.out.println(a+" is a prime.");
+		}else{
+			System.out.println(a+" is not a prime.");
+		}
+	}
+}

SwitchDemo.java

@@ -0,0 +1,20 @@
+import java.util.Scanner;
+class SwitchDemo{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter a number : ");
+		int a = sc.nextInt();
+		String day = null;
+		switch(a){
+			case 0: day = "Sunday";break;
+			case 1: day = "Monday";break;
+			case 2: day = "Tuesday";break;
+			case 3: day = "Wednesday";break;
+			case 4: day = "Thursday";break;
+			case 5: day = "Friday";break;
+			case 6: day = "Saturday";break;
+			default: day = "Error : wrong number input";
+		}
+		System.out.println(day);
+	}
+}

WhileLoopDemo.java

@@ -0,0 +1,19 @@
+import java.util.Scanner;
+class WhileLoopDemo{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter a number : ");
+		int a = sc.nextInt();
+		
+		//while(a>0){
+		//	System.out.println("inside loop a = "+a);
+		//	a--;
+		//}
+		//System.out.println("outside loop");
+		do{
+			System.out.println("inside loop a = "+a);
+			a--;
+		}while(a>0);
+		System.out.println("outside loop");
+	}
+}

WhileLoopDemo2.java

@@ -0,0 +1,24 @@
+import java.util.Scanner;
+class WhileLoopDemo2{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter a number : ");
+		int a = sc.nextInt();
+		int max=0,min=0;
+		//min = Integer.MAX_VALUE;
+		//max = Integer.MIN_VALUE;
+		while(a!=0){
+			a = sc.nextInt();
+			if(a>max){
+				max = a;
+			}
+			if(a<min){
+				min = a;
+			}
+		}
+		System.out.println("min : "+min);
+		System.out.println("max : "+max);
+		System.out.println("loop finished");
+	}
+}
+		

WhileLoopDemo3.java

@@ -0,0 +1,17 @@
+import java.util.Scanner;
+class WhileLoopDemo3{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter a number : ");
+		int a = sc.nextInt();
+		int i=1;
+		while(i<11){
+			System.out.println(a+" * "+i+" = "+i*a);
+			i++;
+			//try{Thread.sleep(5000);}catch(Exception e){}
+		}
+		for(int j=1;j<11;j++){
+			System.out.println(a+" * "+j+" = "+j*a);
+		}
+	}
+}