Vector testGrades contains NUM_VALS test scores. Write a for loop that sets sumExtra to the total extra credit received. Full cr
edit is 100, so anything over 100 is extra credit. Ex: If testGrades = {101, 83, 107, 90}, then sumExtra = 8, because 1 + 0 + 7 + 0 is 8.
1 answer:
Answer:
Here is for loop that sets sumExtra to the total extra credit received. I am writing a program in C++
for(i = 0; i <= testGrades.size() - 1; i++){
if(testGrades.at(i) > 100){
sumExtra = sumExtra + (testGrades.at(i) - 100); } }
Explanation:
The complete program is:
#include <iostream> //to use input output functions
#include <vector> //to use vectors
using namespace std; //to identify objects like cin cout
int main() { //start of main function
const int NUM_VALS = 4; // sets the value of NUM_VALS as a constant to 4
vector<int> testGrades(NUM_VALS); // initialize the vector of int (integer) type
int i = 0; // i is initialzed to 0
int sumExtra = 0; //stores the total extra credit
testGrades.at(0) = 101; //sets 101 at first position in vector
testGrades.at(1) = 83; //sets value 83 at second position
testGrades.at(2) = 107; //sets value 107 at third position
testGrades.at(3) = 90; //sets value 90 at fourth position
for(i = 0; i <= testGrades.size() -1; i++){ //loop iterate through each value of in a vector testGrades
if(testGrades.at(i) > 100){ // if the value in a vector exceeds 100
sumExtra = sumExtra + (testGrades.at(i) - 100); } } //computes total extra credit
cout << "sumExtra: " << sumExtra << endl;} //displays the value of computed total extra credit in output
The loop works as follows:
In the first iteration the value of vector testGrades at(i) is at(0) = 101.
if statement checks if this value/element is greater than 100. This is true as 101 > 100. So sumExtra = sumExtra + (testGrades.at(i) - 100); statement is executed in which 100 is subtracted from that element and the result is added to the sumExtra. sumExtra is initialized to 0 so the value of sumExtra becomes: 0+ 101 - 100= 1 So the value of sumExtra = 1
In the second iteration the value of i = 1 and it is positioned at 2nd value of vector testGrades i.e. 83. Then if statement checks if this value/element is greater than 100. This is false as 83 < 100. So the value of sumExtra = 1
In the third iteration the value of i = 2 and it is positioned at 3rd value of vector testGrades i.e. 107. Then if statement checks if this value/element is greater than 100. This is true as 107 > 100.
sumExtra = sumExtra + (testGrades.at(i) - 100); statement is executed in which 100 is subtracted from that element and the result is added to the sumExtra
sumExtra is 1 so the value of sumExtra becomes: 1+ 107 - 100= 8 So the value of sumExtra = 8
In fourth iteration the value of i = 3 and it is positioned at 4th value of testGrades vector i.e. 90. Then the if statement checks if this element is greater than 100. This is false as 90 < 100. So the value of sumExtra remains 8.
Finally the loop breaks as the value of i becomes 4. So the output is 8.
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Answer:
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int number; //to store each integer value
if(input.hasNextInt()){ //checks if next token in this scanner input is an integer value
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counter=countPos(input); //calls method by passing the Scanner object and stores it in counter variable
if(number>0) //if the value is a positive number
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Explanation:
Here is the complete program:
import java.util.Scanner; //to take input from user
public class Main { //class name
//comments with each line of method below are given in Answer section
static int countPos(Scanner input){
int counter=0;
int number;
if(input.hasNextInt()){
number=input.nextInt();
counter=countPos(input);
if(number>0)
counter++; }
else {
return counter; }
return counter; }
public static void main(String[] args) { //start of main function
System.out.println("Number of positive integers: " + countPos(new Scanner(System.in))); } } //prints the number of positive integers by calling countPos method and passing Scanner object to it
The program uses hasNextInt method that returns the next token (next input value) and if condition checks using this method if the input value is an integer. nextInt() keeps scanning the next token of the input as an integer. If the input number is a positive number then the counter variable is incremented to 1 otherwise not. If the use enters anything other than an integer value then the program stops and returns the total number of positive integers input by the user. This technique is used in order to avoid using any loop. The program and its output is attached
