Java Methods That Affect MATLAB Commands

MATLAB^® commands that operate on Java^® objects and arrays use the methods that are implemented within, or inherited by, the class. There are some MATLAB commands that you can alter in behavior by changing the Java methods that they use.

Changing the Effect of `disp` and `display`

You call the disp function when you:

Display the value of a variable or an expression in MATLAB.
Terminate a command line without a semicolon.
Display a Java object in MATLAB.

When calling disp on a Java object, MATLAB formats the output using the object toString method. If the class does not implement this method, then MATLAB uses an inherited toString method. If no intermediate ancestor classes define this method, MATLAB uses the toString method defined by the java.lang.Object class.

To change the way MATLAB displays an object, implement your own toString method in your class definition.

Changing the Effect of `isequal`

The MATLAB isequal function compares two or more arrays for equality in type, size, and contents. Also, you can use this function to test Java objects for equality.

When you compare two Java objects using isequal, MATLAB performs the comparison using the Java method, equals. MATLAB first determines the class of the objects specified in the command, and then uses the equals method implemented by that class. If equals is not implemented in this class, then MATLAB uses an inherited equals method. If no intermediate ancestor classes define this method, MATLAB uses the equals method defined by the java.lang.Object class.

To change the way MATLAB compares members of a class, implement your own equals method in your class definition.

Changing the Effect of `double`, `string`, and `char`

You can change the output of the MATLAB double, string, and char functions by defining your own Java methods, toDouble, toString, and toChar. For more information, see Convert to MATLAB Numeric Types and Convert to MATLAB Strings.