PPT Slide

Java Constructors

Motivation: We need a means of initializing the attributes of a new object (or “instance”) when it is created.

Means: “Constructor methods” that are invoked automatically upon “instantiation” (creation) of new object.

Example:

public Box (int iNewLength, int

iNewWidth, int iNewHeight) {

setLength (iNewLength);

setWidth (iNewWidth);

setHeight (iNewHeight);

} // of constructor

Note: Constructor method has same identification as the class.

Can now do:

Box subwooferBox =

new Box (46, 46, 82);

Equivalent to:

Box subwooferBox = new Box; subwooferBox.setLength(46); subwooferBox.setWidth(46); subwooferBox.setHeight(82);