以下代碼在編譯並運行時會將輸出顯示爲「alpha subsub」。 SubSubAlpha();
構造函數應該將「subsub」添加到變量s
並且應該是輸出。使用構造函數創建新對象
輸出是「alpha subsub」怎麼樣?
class Alpha {
static String s = " ";
protected Alpha() {
s += "alpha ";
}
}
public class SubSubAlpha extends Alpha {
private SubSubAlpha() {
s += "subsub ";
}
public static void main(String[] args) {
new SubSubAlpha();
System.out.println(s);
// This prints as " alpha subsub".
//Shouldn't this one be printed as " subsub"
//Who made the call to Alpha(); ?
}
}
您擴展阿爾法類,因此這種構造類首先被調用。 –