Arrays can be declared in the following ways:
int a[6]
This creates an array with six integer elements. The elements are indexed from 0 to 5 (not 1 to 6). You need to fill in the elements before trying to access them. Elements are accessed like this:
a[0] = 6;
Alternatively you can declare an array with an initialiser.
int[ ] a = { 1 , 2 , 3 };
Note the space between the square brackets. It is important that there is exactly one space there.
You cannot combine the two ways of creating an array, i.e. you cannot declare the size and give the array an initialiser in the same statement.
Multi-dimensional arrays are used like this:
int m[5][5]; m[2][3] = 12;
or they can be declared like this, nesting the initialisers.
String[ ][ ] names = { { "john" , "phil" } , { "jones" , "smith" } };
To copy the contents of one array into another, use the arraycopy
function.
int[ ] a = { 1 , 2 , 3 }; int[ ] b = { 7 , 8 , 9 }; arraycopy( b , a );
This code copies the elements of array b into the corresponing elements of array a. So both arrays will end up containing the numbers 7, 8, 9.