ADT Spec

Here is the ADT spec for the method "size".

size();
	/*
	Return number of elements in this list.
	*/

Code

Utilizing our ivar listing in our coded object structure we note that "_size" is an ivar. Thus all we need to do is return it.

size() {
	return this._size;
}

ADT Spec

Here is the ADT spec for the method "get".

get(index);
	/*
	Return element at given index.
	If passed arg "index" is invalid, throws exception:
		"(get) Index %d is out of bounds"
	*/

Code

Here is the code for "get".

get(index) {
	if (index < 0 || index >= this.size())
		throw '(get) Attempt to access element in empty list';
	return this.fixedArray[index];
}

ADT Spec

Here is the ADT spec for the method "add". We see that this one is trivial, we simply call "addLast".

add(newElem);
	/*
	Alias for "addLast" (same functionality).
	*/

Code

Doesn't get any easier than this. Just pass the logic to our friend "addLast".

add(newElem) {
	this.addLast(newElem);
}

Required Instance Method Header

Assume the problem requirements include this required method header.

We know the instance variables from the object structure coding.

addLast(newElem);
	/*
	Add (append) the passed arg "newElem" to end of list
	All existing elements are preserved and will precede (be before) "newElem".
	No return value
	Example:
		given "this" dynamic list is [10, 20, 30, 40]
		and "(newElem)" is (1002)
	Then, after "addLast" is finished, the result:
		"this" dynamic list is [10, 20, 30, 40, 1002]
	*/

Coding 'addLast'

Here is the code for "addLast". We are utilizing several helper methods (which we'll also need to code).

addLast(newElem) {
	//Add the passed arg "newElem" to end of list
	if (!this.hasCapacity())
	    this.grow();
	this.fixedArray[this.size()] = newElem;
	this._size++;
}

Coding 'hasCapacity'

Here is the code for "addLast". We are utilizing several helper methods (which we'll also need to code).

hasCapacity() {
	// Return true if our capacity is greater than our size
	// i.e. if we have excess capacity
	return this.getCapacity() > this.size();
}

getCapacity() {
	return this.fixedArray.length;
}

Coding 'grow'

Here is the code for "addLast". We are utilizing several helper methods (which we'll also need to code).

grow() {
	// Grow (increase) our capacity by factoring our
	//current capacity by the input param "growthFactor"
	// In this method var "fa" will be the new fixed array
	this.growCapacityTo((int)Math.round(getCapacity() * this.growthFactor));
}

growCapacityTo(newCapacity) {
	// Grow (increase) our capacity to "newCapacity"
	// Construct new fixed array
	// Copy existing elements into new fixed array
	let oldFixedArray = this.fixedArray;
	let newFixedArray = this.newFixedArray(newCapacity);
	//Copy
	for (let i = 0; i < this.size(); i++)
		newFixedArray[i] = oldFixedArray[i];
	this.fixedArray = newFixedArray;
}