1st

Apex Program for Array Operations :

public class ArrayOperation {
public static void SumAndAverage(){
Integer[] myArr = new Integer[]{5,4,6,8,1};
Integer sum = 0;
Integer smallest = myArr[0];
Integer greatest = myArr[0];

    Integer i = 0;
    while(i < myArr.size()) {
        sum = sum + myarr[i];
        
        if(myarr[i] < smallest){
            smallest = myArr[i];
        }
        
        if(myarr[i] > greatest){
            greatest = myArr[i];
        }
         i++;
    }
    
    Decimal average = sum / myArr.size();
    
    system.debug('The Sum of array elements Are : ' + sum);
    system.debug('The Average of sum is : ' + average);
    system.debug('The smallest element of array is : ' + smallest);
    system.debug('The greatest elements of array is : ' + greatest);
}

}