英文:
How can my 2nd constructor parameter work?
问题
import java.util.Scanner;class BloodData {static Scanner in = new Scanner(System.in);static String bloodType;static String rhFactor;public BloodData() {bloodType = "O";rhFactor = "+";}public BloodData(String bt, String rh) {bloodType = bt;rhFactor = rh;}public void display() {System.out.println(bloodType + rhFactor + " is added to the blood bank");}public static void main(String[] args) {System.out.println("Enter Blood Type(O, A, B, AB)");System.out.println("Enter rhFactor('+' or '-')");BloodData bd = new BloodData(BloodData.bloodType = in.nextLine(), BloodData.rhFactor = in.nextLine());BloodData bd1 = new BloodData();bd.display();}}
英文:
import java.util.Scanner;class BloodData{static Scanner in = new Scanner(System.in);static String bloodType;static String rhFactor;public BloodData(){bloodType = "O";rhFactor = "+";}public BloodData(String bt, String rh){bloodType = bt;rhFactor = rh;}public void display() {System.out.println(bloodType+rhFactor+" is added to the blood bank");}public static void main(String[]args) {System.out.println("Enter Blood Type(O, A, B, AB)");System.out.println("Enter rhFactor('+' or '-')");BloodData bd= newBloodData(BloodData.bloodType=in.nextLine(),BloodData.rhFactor=in.nextLine());BloodData bd1= new BloodData();bd.display();}}
How can i use the constructor with 2 String parameters? because when I always run the code the first one only run. I'm only a beginner so hope someone could help because I already watched a lot of Youtube vids and I really didn't know why this happens
答案1
得分: 1
Java不使用像这样的命名参数来调用方法或构造函数。如果有视频展示这样的语法，我会感到惊讶...
new BloodData(BloodData.bloodType=in.nextLine(), BloodData.rhFactor=in.nextLine())
你需要在上一行中定义String变量，然后将它们传递给构造函数。你也不应该将实例构造函数与静态变量结合使用。
class BloodData {private String bloodType;private String rhFactor;public BloodData(String type, String rhFactor) {this.bloodType = type;this.rhFactor = rhFactor;}// 其他代码...public static void main(String[] args) {Scanner in = new Scanner(System.in);String x = in.nextLine();String y = in.nextLine();BloodData bd = new BloodData(x, y);}}
英文:
Java doesn't use named parameters like this for method or constructors. I would be surprised if a video showed such syntax...
new BloodData(BloodData.bloodType=in.nextLine(),BloodData.rhFactor=in.nextLine())
You need to define String variables on the line above, then pass them into the constructor. You also shouldn't be combining instance constructors with static variables
class BloodData{private String bloodType;private String rhFactor;public BloodData(String type, String rhFactor) {this.bloodType = type;this.rhFactor = rhFactor;}...public static void main(String[] args) {Scanner in = new Scanner(System.in);String x = in.nextLine();String y = in.nextLine();BloodData bd = new BloodData(x, y);}
答案2
得分: 0
如果你想调用一个有两个参数的构造函数：使用 this
BloodData blooddata = new BloodData("A", "+");
英文:
if you want to call a constructor having two parameters: Use this
BloodData blooddata = new BloodData("A","+");
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