Java Reference
In-Depth Information
String[] name = new String[3]; // A local array variable
for (int i = 0; i < name.length; i++) {
System.out.println("name[" + i + "]:" + name[i]);
}
}
}
int array initialization:
empId[0]:0
empId[1]:0
empId[2]:0
boolean array initialization:
bArray[0]:false
bArray[1]:false
bArray[2]:false
Reference type array initialization:
name[0]:null
name[1]:null
name[2]:null
Beware of Reference Type Arrays
Array elements of a primitive type contain values of that primitive type, whereas array elements of a reference type
contain the reference of objects. Suppose you have an
int
array of
int[] empId = new int[5];
Here,
empId[0]
,
empId[1]...empId[4]
contain an
int
value.
Suppose you have an array of
String, like so:
String[] name = new String[5];
Here,
name[0], name[1]...name[4]
may contain a reference of a
String
object. Note that the
String
objects, the
elements of the
name
array, have not been created yet. As discussed in the previous section, all elements of the
name
array contain
null
at this point. You need to create the
String
objects and assign their references to the elements of
the array one by one as shown:
name[0] = new String("name1");
name[1] = new String("name2");
name[2] = new String("name3");
name[3] = new String("name4");
name[4] = new String("name5");
