JAVA Dynamic Array

Question

I will post my code and hope someone can tell what to change to make a "dynamic array"? The current code works but they told me it is not the correct way and instead of this I need to make a dynamic array. Thanks in advance.

public static void main(String[] args) {

int i,a,b;
int [] array1 = new int[20];//{12,23, -22, 0, 43,545, -4, -55,43, 12,0, -999, -87

array1[0] = 12;
array1[1] = 23;
array1[2] = -22;
array1[3] = 0;
array1[4] = 43;
array1[5] = 545;
array1[6] = -4;
array1[7] = -55;
array1[8] = 43;
array1[9] = 12;
array1[10] = 0;
array1[11] = -999;
array1[12] = -87;

int [] arrayPlus = new int[20];
int [] arrayMinus = new int[20];


a=b=0;


for (i = 0; i < 13; i++) {
    if (array1[i] > 0 || array1[i] == 0) {
        arrayPlus[a] = array1[i];
        a++;
    } else {
        arrayMinus[b] = array1[i];
        b++;
    }
}
System.out.println("Positive array numbers");
for (i = 0; i < a; i++) {
System.out.println(arrayPlus[i]);}


System.out.println("");

System.out.println("Negative array numbers");
for (i = 0; i < b; i++) {
System.out.println(arrayMinus[i]);}

}
}

Maybe they're asking for an array that's initialised with a variable length at runtime? Or maybe they're referring to [ArrayLists](https://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html)? Could you tell us what the code is supposed to be doing? — PakkuDon, Dec 17 '15 at 09:58

score 0 · Answer 1 · answered Dec 17 '15 at 10:25

Please check the below code

      import java.util.Scanner;
      class DynamicArray {
      public static void main(String[] args) {

      int i,a,b;
      System.out.println("Enter the limit of array :" );
      Scanner s = new Scanner(System.in);
      int limit = s.nextInt();
      int [] array1 = new int[limit];//{12,23, -22, 0, 43,545, -4, -55,43, 12,0, -999, -87

      System.out.println("Enter the numbers");
      for(i=0; i<limit; i++)
      {
          array1[i] = s.nextInt();
      }
      int [] arrayPlus = new int[limit];
      int [] arrayMinus = new int[limit];


     a=b=0;


    for (i = 0; i < limit; i++) {
         if (array1[i] > 0 || array1[i] == 0) {
              arrayPlus[a] = array1[i];
              a++;
        } else {
              arrayMinus[b] = array1[i];
              b++;
        }
   }
   System.out.println("Positive array numbers");
   for (i = 0; i < a; i++) {
       System.out.println(arrayPlus[i]);}


       System.out.println("");

       System.out.println("Negative array numbers");
       for (i = 0; i < b; i++) {
            System.out.println(arrayMinus[i]);}

       }
 }

Works for me but Im waiting to see what the professor says. I let you know. Thank You for your help friend. — exwhy990, Dec 17 '15 at 10:31

JAVA Dynamic Array

1 Answers1