Js中にAraryListを実現

/**********************************************************

  * JavaScript   ArrayList  

  * 

  * @author {yangl}

  * @version $Revision: 0.5 $ $Date: 8/04/15:00:$

  * @description

  * Method:

 * add(element);

 * addElementAt(index, element);

 * contains(element);

 * get(index);

 * isEmpty(index);

 * indexOf(element);

 * lastIndexOf(element);

 * remove()

 * setElementAt(index, element);

 * size();

 * toString();

 * toArray();

 * @example

 * var arrList = new ArrayList();

 * //var arrList = new ArrayList(10);

 * arrList.add("");

 * arrList.add("");

 * arrList.add("");

 *

 *********************************************************/

 // JavaScript ArrayList

 /**

 Method:

        add(element);

        addElementAt(index, element);

        contains(element);

        get(index);

        isEmpty(index);

        indexOf(element);

        lastIndexOf(element);

        remove(index);

        setElementAt(index, element);

        size();

        toString();

 */

 /**

 Example:

        var arrList = new ArrayList();

        //var arrList = new ArrayList(10);

        arrList.add("");

        arrList.add("");

        arrList.add("");

 */

var ArrayList = function () {

    var args = ArrayList.arguments;

    var initialCapacity = 10;



    if (args != null && args.length > 0) {

        initialCapacity = args[0];

    }



    var elementData = new Array(initialCapacity);

    var elementCount = 0;



    this.size = function () {

        return elementCount;

    };



    this.add = function (element) {

        //alert("add");

        ensureCapacity(elementCount + 1);

        elementData[elementCount++] = element;

        return true;

    };



    this.addElementAt = function (index, element) {

        //alert("addElementAt");

        if (index > elementCount || index < 0) {

            alert("IndexOutOfBoundsException, Index: " + index + ", Size: " + elementCount);

            return;

            //throw (new Error(-1,"IndexOutOfBoundsException, Index: "+index+", Size: " + elementCount));

        }

        ensureCapacity(elementCount + 1);

        for (var i = elementCount + 1; i > index; i--) {

            elementData[i] = elementData[i - 1];

        }

        elementData[index] = element;

        elementCount++;

    };



    this.setElementAt = function (index, element) {

        //alert("setElementAt");

        if (index > elementCount || index < 0) {

            alert("IndexOutOfBoundsException, Index: " + index + ", Size: " + elementCount);

            return;

            //throw (new Error(-1,"IndexOutOfBoundsException, Index: "+index+", Size: " + elementCount));

        }

        elementData[index] = element;

    };



    this.toString = function () {

        //alert("toString()");

        var str = "{";

        for (var i = 0; i < elementCount; i++) {

            if (i > 0) {

                str += ",";

            }

            str += elementData[i];

        }

        str += "}";

        return str;

    };



    this.get = function (index) {

        //alert("elementAt");

        if (index >= elementCount) {

            alert("ArrayIndexOutOfBoundsException, " + index + " >= " + elementCount);

            return;

            //throw ( new Error( -1,"ArrayIndexOutOfBoundsException, " + index + " >= " + elementCount ) );

        }

        return elementData[index];

    };



    this.remove = function (index) {

        if (index >= elementCount) {

            alert("ArrayIndexOutOfBoundsException, " + index + " >= " + elementCount);

            //return;

            throw (new Error(-1, "ArrayIndexOutOfBoundsException, " + index + " >= " + elementCount));

        }

        var oldData = elementData[index];

        for (var i = index; i < elementCount - 1; i++) {

            elementData[i] = elementData[i + 1];

        }

        elementData[elementCount - 1] = null;

        elementCount--;

        return oldData;

    };



    this.isEmpty = function () {

        return elementCount == 0;

    };



    this.indexOf = function (elem) {

        //alert("indexOf");

        for (var i = 0; i < elementCount; i++) {

            if (elementData[i] == elem) {

                return i;

            }

        }

        return -1;

    };



    this.lastIndexOf = function (elem) {

        for (var i = elementCount - 1; i >= 0; i--) {

            if (elementData[i] == elem) {

                return i;

            }

        }

        return -1;

    };



    this.contains = function (elem) {

        return this.indexOf(elem) >= 0;

    };



    this.toArray = function () {

        var resultArray = new Array(this.size());

        for (var i = 0; i < this.size(); i++) {

            resultArray[i] = elementData[i];

        }

        return resultArray;

    };



    function ensureCapacity(minCapacity) {

        var oldCapacity = elementData.length;

        if (minCapacity > oldCapacity) {

            var oldData = elementData;

            var newCapacity = parseInt((oldCapacity * 3) / 2 + 1);

            if (newCapacity < minCapacity) {

                newCapacity = minCapacity;

            }

            elementData = new Array(newCapacity);

            for (var i = 0; i < oldCapacity; i++) {

                elementData[i] = oldData[i];

            }

        }

    }

};