Java: How can i remove null value from a string? -

When this code is run, it outputs to nulli . Why is this doing?

  public static zero main (string [] args) {string [] a = new string [1]; String m = null; String c = "hi"; For (int i = 0; i & lt; c.length (); i ++) {a [0] = a [0] + c. Art et al. (I); } System.out.print (a [0]);  

Before the loop, type:

  A [0] = "";  

i.e.

  public static zero main (string [] args) {string [] a = new string [1]; String m = null; String c = "hi"; A [0] = ""; For (int i = 0; i & lt; c.length (); i ++) {a [0] = a [0] + c. Art et al. (I); } System.out.print (a [0]); }