External Interfaces/API

Creating a New Array Reference

Because Java arrays in MATLAB are references, assigning an array variable to another variable results in a second reference to the array.

Consider the following example where two separate array variables reference a common array. The original array, origArray, is created and initialized. A copy of this array variable is created by the statement newArrayRef = origArray. Changes made to the array referred to by newArrayRef also show up in the original array.

origArray = javaArray('java.lang.Double', 3, 4);
for i = 1:3
    for j = 1:4
    origArray(i,j) = java.lang.Double((i * 10) + j);
    end
end

origArray
origArray =
java.lang.Double[][]:
    [11]    [12]    [13]    [14]
    [21]    [22]    [23]    [24]
    [31]    [32]    [33]    [34]

%  ----- Make a copy of the array reference -----
newArrayRef = origArray;
newArrayRef(3,:) = java.lang.Double(0);

origArray
origArray =
java.lang.Double[][]:
    [11]    [12]    [13]    [14]
    [21]    [22]    [23]    [24]
    [ 0]    [ 0]    [ 0]    [ 0]

Concatenating Java Arrays

Creating a Copy of a Java Array