TurkuBasicOOPinJava / Week 2: Methods, strings and lists /17b. Count positive and negative elements
KaiquanMah's picture
Create 17b. Count positive and negative elements
9b478da verified
The program has a preformatted list variable numbers, which points to an integer-type list.
Your task is to count how many negative and how many positive elements there are in the list.
Print the result as shown in the example below:
Example execution:
Positives: 10
Negatives: 6
import java.util.Random;
import java.util.ArrayList;
public class Test{
public static void main(String[] args){
final Random rnd = new Random();
for (int test=1; test<=3; test++) {
System.out.println("Test number " + test);
// initialise an Integer list
ArrayList<Integer> numbers = new ArrayList<>();
// random int from 0 to 15 (excluding 15)
// add 10 to it: 10-24
int length = 10 + rnd.nextInt(15);
// for the 10-24 integers
// random int from 0 to 30 (excluding 30)
// each element = 15 - rand_int_0_uptobutnotincl30
for (int i=0; i<length; i++) {
numbers.add(15 - rnd.nextInt(30));
}
System.out.println("List: " + numbers);
//ADD
int pos=0;
int neg=0;
for (int num: numbers) {
if (num>0) {
pos++;
}
else if (num<0) {
neg++;
}
}
System.out.println("Positives: " + pos);
System.out.println("Negatives: " + neg);
System.out.println("");
}
}
}
Test number 1
List: [5, 7, 7, -13, 11, -13, 11, -3, -2, 6, 0, 14, 1, 13, -6, 6, -8, 15, -13, -10, 6]
Positives: 12
Negatives: 8
Test number 2
List: [-13, 6, 7, -7, 9, -6, 0, -7, -8, -13, 6, -9, -10, -10, -10, 10, -7, -2, -5, -8, 13, -8, 9, -12]
Positives: 7
Negatives: 16
Test number 3
List: [-14, 12, 15, 0, -2, -1, 7, 13, 14, 11, -4, 1, 9, 3, 1]
Positives: 10
Negatives: 4