Over writing an array vs. Deleting and re-initializing it? Java

Question

is overwriting an array in java the same as deleting the elements and inserting new ones? I have a 50x50 array that stores floating point values. A method calculates new values and sends them to the same array that already has these values for overwriting the previous ones. This is a recurring procedure. After around 1500 iterations, stackoverflow error occurs. Would it be different if I set the array to null first before writing values to it?

Answer 1

The code is:

    float n = input.nextFloat();
    public static void calculate_initial_float_values(){

    for(int i = 0; i < a.length; i++){ 
      for(int j = 0; j < a.length; j++){

      a[i][j] = i+j+n*n ; 
      } 
    }
      change_values();
  }

    public static void change_values(){
        n = rng.Random(9);
        calculate_initial_float_values(); 
  }