我有一個(gè)魔方課，內(nèi)容如下：public class Rubik{ private int[][][] grid; protected Face[] cube; protected Face up; protected Face left; protected Face front; protected Face right; protected Face down; protected Face back; private static String dots = "......"; private String output; //Constructor public Rubik(int[][][] grid){ int[][][] copy_grid = new int[6][3][3]; for (int k = 0; k < 6; k++){ for (int i = 0; i < 3; i++){ for (int j = 0; j < 3; j++) copy_grid[k][i][j] = grid[k][i][j]; } } this.grid = copy_grid; this.up = new Face(grid[0]); this.left = new Face(grid[1]); this.front = new Face(grid[2]); this.right = new Face(grid[3]); this.down = new Face(grid[4]); this.back = new Face(grid[5]); this.cube = new Face[]{this.up, this.left, this.front, this.right, this.down, this.back}; }我正在嘗試創(chuàng)建一個(gè)擴(kuò)展 Rubik 的 RubikRight 類，并且 RubikRight 的定向方式使得原始 Rubik 的右面現(xiàn)在面向前方。這就是我為 RubikRight 定義構(gòu)造函數(shù)的方式：public class RubikRight extends Rubik{ //Constructor public RubikRight(int[][][] grid){ int[][][] copy_grid = new int[6][3][3]; for (int k = 0; k < 6; k++){ for (int i = 0; i < 3; i++){ for (int j = 0; j < 3; j++) copy_grid[k][i][j] = grid[k][i][j]; } } this.grid = copy_grid; this.up = new Face(grid[0]); this.left = new Face(grid[2]); this.front = new Face(grid[3]); this.right = new Face(grid[5]); this.down = new Face(grid[4]); this.back = new Face(grid[1]); this.cube = new Face[]{this.up, this.left, this.front, this.right, this.down, this.back}; }我可以知道為什么我似乎無法這樣定義 RubikRight 嗎？
2 回答
繁星淼淼
TA貢獻(xiàn)1775條經(jīng)驗(yàn) 獲得超11個(gè)贊
每當(dāng)實(shí)例化子類對(duì)象時(shí)，都會(huì)隱式調(diào)用父類默認(rèn)構(gòu)造函數(shù)。因此，當(dāng)您RubikRight通過調(diào)用它來實(shí)例化時(shí)，會(huì)從 RubikRight 的構(gòu)造函數(shù)內(nèi)部new RubikRight(int[][][])隱式調(diào)用。super()因此出現(xiàn)錯(cuò)誤：
required: int[][][] // what you have in Rubik class, note that you don't have the default constructor
found: no arguments // super(/* no argument */) called implicitly
要消除錯(cuò)誤，您有兩種選擇：
要么super(grid)從RubikRight構(gòu)造函數(shù)顯式調(diào)用。
或者，在（基）類中實(shí)現(xiàn)默認(rèn)構(gòu)造函數(shù)Rubik。
紫衣仙女
TA貢獻(xiàn)1839條經(jīng)驗(yàn) 獲得超15個(gè)贊
您沒有調(diào)用父類的構(gòu)造函數(shù)。
這里你可以做的是，重載父類中的構(gòu)造函數(shù)。創(chuàng)建默認(rèn)構(gòu)造函數(shù)（無參數(shù)構(gòu)造函數(shù)）并使其受保護(hù)。
public class Rubik{
...
protected Rubik() {
}
}
這應(yīng)該可以解決你的問題。
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