A String array can be declared as String[] strArr = null; Provided, this reference variable is pointing a well defined string array.

Incorrect way

String[] strArray = null;
for(int i = 0; i < 10; i++){
  strArray[i] = "a"+i;
}

This will throw nullPointer exception

Correct way

String[] strArray = null;
String[] strArray1 = {"Shiv", "Umar","Satya","Abhishek"};
strArray = strArray1;