java - How to create an Array without knowing the length it will have -

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• java dynamic array sizes? 16 answers

i've got problem solve follows:

create method returns array contains positive values of int[] a

i've kinda solved writing method:

public static int[] solopositivi(int[] a) {     int[] pos = new int[a.length];     int j=0;      (int i=0; i<a.length; i++){         if (a[i]>0) {             pos[j] = a[i];             j++;         }     }     return pos; } 

of course when test using example:

int[] = new int[] {2,-3,0,7,11}; 

i [2,7,11,0,0], because set:

int[] pos = new int[a.length]; 

the question is, how pos array have modular length can [2,7,11], without having use lists? have solve problem using arrays methods.

first, loop through , count number of positive elements know length, loop through again copy.

public static int[] copypositivevals(int[] arr) {     int count = 0;     for(int x : arr) {         if (x > 0) count++;     }      int[] arr2 = new int[count];     int = 0;     for(int x : arr) {         if (x > 0) {              arr2[i] = x;              i++;         }     }     return arr2; }