無法用Java創建對象數組

Question

這是我的觀點：我需要使用默認的woodType創建一個Chair對象數組。 我能夠聲明數組本身，但顯然所有的值都是null。 當我嘗試實例化數組中的每個Chair對象時，我會收到錯誤。 在嘗試實例化時我不確定我做錯了什么，請幫忙。

public class PAssign3 {

public static void main(String[] args) {

    TableSet set1 = new TableSet();

    TableSet set2 = new TableSet(5, 7, 4);
//        Chair chr1 = new Chair();//this works properly, setting wood as Oak
//        Chair chr2 = new Chair("Pine");//works

    }

}

class TableSet {

    Table table = new Table();

    private int numOfChairs = 2;

    //creates an array that can hold "numOfChairs" references to same num of 
    //chair objects; does not instantiate chair objects!!!
    Chair[] chairArr = new Chair[numOfChairs];

    //instantiate each chair object for length of array
    //this loop does not work; Error: illegal start of type
    for (int i = 0; i < numOfChairs.length; i++) {
        chairArr[i] = new Chair();
        }

    public TableSet() {
    }

    public TableSet(double width, double length, int numOfChairs) {
        table = new Table(width, length);
        this.numOfChairs = numOfChairs;
        chairArr = new Chair[numOfChairs];

        //this loop also does not work; Error: int cannot be dereferenced
        for (int i = 0; i < numOfChairs.length; i++) {
            chairArr[i] = new Chair();
        }
    }

    public void setNumOfChairs(int numOfChairs) {
        this.numOfChairs = numOfChairs;
    }

    public int getNumOfChairs() {
        return numOfChairs;
    }

    public String getChairWoodType() {
        return chairArr[0].getWoodType();
    }
}

class Table {

    private double width = 6;
    private double length = 4;

    public Table() {
    }

    public Table(double width, double length) {
        this.width = width;
        this.length = length;
    }

    public void setWidth(double width) {
        this.width = (width < 0) ? 0 : width;
    }

    public void setLength(double length) {
        this.length = (length < 0) ? 0 : width;
    }

    public double getWidth() {
        return width;
    }

    public double getLength() {
        return length;
    }
}

class Chair {

    private String woodType = "Oak";

    public Chair() {
    }

    public Chair(String woodType) {
        this.woodType = woodType;
    }

    public void setWoodType(String woodType) {
        this.woodType = woodType;
    }

    public String getWoodType() {
        return woodType;
    }
}

Answer 1

int是Java中的簡單類型，沒有任何方法或字段。 省略這個.length ，錯誤就消失了。 在我看來它已經存儲了實際的椅子數量（2）。