java - 无法使用 getName 从数组中获取要显示的名称

Question

我目前正在使用 java，但还没有掌握一切，所以请耐心等待。我一直试图让我的名字出现在输出菜单上，但我的代码中一定遗漏了一些东西。这是我的代码，它有一个驱动程序类和客户端类：

import java.util.Scanner;

//This is TestBaby.java class
public class TestBaby {

// This is main() method, program execution start from here
public static void main(String[] args) {
    // This is Scanner class object, it will help to take value from end user
    Scanner scan = new Scanner(System.in);

    //This is array object of Baby type
    Baby[] babies = new Baby[4];

    //This is for loop, it iterates 4 times for holding 4 Babies data
    for(int i=0; i<4; i++) {
    
        //a. Enter details for each baby (name and age) and thus populate the Baby array
        System.out.println("Enter details of " + "Baby " +(i+1));
        
        if(i!=0)               
          scan.nextLine();
        
        System.out.println("Enter name: ");
        String name = scan.nextLine();

        System.out.println("Enter age: ");
        int age = scan.nextInt();

        //This is Baby class object*/
        Baby baby = new Baby();
        //Set name in Baby class object whatever user entered
        baby.setName(name);
        //Set age in Baby class object whatever user entered
        baby.setAge(age);
        //Store current Baby class object into babies array
        babies[i] = baby;
    }//for end 

    //b. Output the details of each baby from the array (name and age)
    int i=0;
    for(Baby baby : babies) {
        System.out.println("Baby name: " + baby.getName());
        System.out.println("Baby age: "  + baby.getAge());
        i++;
    }

    //c. Calculate and display the average age of all babies in the array
    double averageAge = averageAge(babies);
    System.out.println("Average age of all babies: "+averageAge);

    //d. Determine whether any two babies in the array are the same
    for(i=0; i<babies.length; i++) {
        for(int j=i+1; j<babies.length; j++) {
            System.out.println(babies[i].getName()+ " and " + babies[j].getName() + " are equal? " + babies[i].equals(babies[j]));
        }//inner for loop
    }//outer for loop
}//main() end

//This is averageAge() method, it will calculate average age of Babies
public static double averageAge(Baby[] babies) {
    //These are local variables of averageAge() method
    int size = babies.length;
    double averageAge = 0.0;

    //This is for loop, it will calculate total age of babies
    for(int i=0; i<size; i++) {
        averageAge = averageAge + babies[i].getAge();
    }//for end

    //return average age to caller of this method
    return averageAge/size;
}//averageAge() end
}// TestBaby end

  //This is Baby.java class
 public class Baby {
//These are instance variable of Baby.java class
private String name;
private int age;

//This is default constructor
public Baby() {
    name = "Baby";
    age = 1;
}

//This is parameterized constructor will take two parameters, a string to set the name and an integer to set the age
public Baby(String name, int age) {
    this.name = name;
    this.age = age;
}

//Supply methods for setting the name, setting the age, getting the name and getting the age.
public String getName() {
    return name;
}

public void setName(String name) {
//The set method for the name instance variable should ensure that the input is not empty or contain whitespaces (otherwise set a default value)
    if (name.trim().isEmpty()){
        this.name = "Baby";
        this.name = name;
    }
}

public int getAge() {
    return age;
}

public void setAge(int age) {
    //The set method for the age instance variable should validate the input to be between 1 and 4 inclusive (otherwise set a default value).
    if (age >= 1 && age <= 4) {
        this.age = age;
    } //if end
    else {
        this.age = 1;
    }//else end
}// setAge() end

//Give Java code for an equals method for the Baby class.
@Override
public boolean equals(Object obj) {
    //This is type casting
    Baby baby = (Baby)obj;

    //Compare name and age of Baby, if both are same then return true otherwise return false
    if(this.age == baby.age && this.name.equalsIgnoreCase(baby.name))
        return true;
        return false; 
}//equals() end 
}// Baby end

请先尝试代码，以便您理解我的意思，以防它不清楚

标签： java

Answer 1

Baby.setName(String name)仅在name为空时设置名称。你的方法：

public void setName(String name) {
    if (name.trim().isEmpty()){
        this.name = "Baby";
        this.name = name;
    }
}

尝试这个：

public void setName(String name)
{
  if (name == null)   ​
 ​ {
    // Use default from constructor
    return;
  }

  String n = name.trim();

  if (!n.isEmpty())
  ​{
    ​this.name = n;
  }
}