Question

Using Java write all 4 methods in one class

1) Write a value-returning method that returns the number of elements in an integer array.

2) Write a void method that multiples by 2 all the elements in an array of float.

3) Write a value- returning method that returns the product of all elements in an integer array.

4) Write a method that returns the total # of elements greater or equal to 90 in an array of integers.

Answer 1

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CODE:

public class Main
{
   public static void main(String[] args) {
   int numInt[] = {102, 100, 60, 50, 120, 140, 80, 40};//creating an array of integer
   double numFLoat[] = {1.2, 2.2, 4.4, 5.78, 11.24, 98.22};//creating an array of double
   System.out.println("Number of elements in array: ");
System.out.println(numElems(numInt));//calling the method numElems
System.out.println("After multiplying the each element of array with 2: ");
mul(numFLoat);//calling the method numFloat
System.out.println("The product of all elements of array: ");
System.out.println(prod(numInt));//calling the method prod
System.out.println("Elements of array which are greater then or equal to 90");
System.out.println(total(numInt));//calling the method total
   }
   public static int numElems(int arr[]) {//method for finding length of integer array
       int len = arr.length;
       return len;
   }
   public static void mul(double arr[]) {//method for multiplying double array with 2
   double res = 0.0;
   for (int i = 0; i < arr.length; i++) {
   res = 2 * arr[i];
   System.out.println(res);
   }
   }
   public static int prod(int arr[]) {//method for product of each array element
   int res = 1;
   for (int i = 0; i < arr.length; i++) {
   res = res * arr[i];
   }
   return res;
   }
   public static int total(int arr[]) {//method for finding elements greater then 90
   for (int i = 0; i < arr.length; i++) {
   if(arr[i] >= 90) {
   System.out.println(arr[i]);//printing elements
   }
   }
return 0;
   }
}

OUTPUT: