So I have this project I am working on and I need to create my own ArrayList class for it. I have all my methods defined, but when I compile I keep getting a "cannot find symbol" error for three of my methods. I have an interface that looks like this:
public interface FBList {
public int size();
public void insert(int i, Person person);
public Person remove(int i);
public Person lookUp(int i);
/**
*A class that defines a person
**/
public class Person {
private String id;
private long phoneNum;
public Person(String personID, long phoneNum){
id = personID;
phoneNum = phoneNum;
}
}
As you can see, I have an inner class in there. I am trying to use that class in my other file which implements this interface. Currently, the three methods in my other file giving me the issue are as follows:
/**
* A method to expand the size of the array if the array is too small
* @param i One minus the place in the list where the component will be inserted
* @param Person The person to be put in the list
**/
protected void expandInsert(int i, Person person){
Person[] temp = new Person[arrayList.length * 2];
for(int index = 0; index < temp.length; index++){
if( i != index){
if(i > 0)
temp[index] = arrayList[index];
if(i == 0)
temp[index + 1] = arrayList[index];
}
else{
temp[i] = person;
i = 0;
index--;
}
}
arrayList = temp;
}
/**
* Inserts a new component at the end of a list by creating a new list longer that then last
* @param i The place in the list where the component will be inserted
* @param Person The person to be added to the list
**/
protected void insertAtEnd(int i, Person person){
Person[] temp = new Person[arrayList.length + 5];
for(int index = 0; index < temp.length; index++){
if(index != i){
temp[index] = arrayList[index];
}
else{
temp[index] = person;
}
}
arrayList = temp;
}
/**
* Shrinks the array by one by removing one component from the array
* @param i The index to be removed
**/
protected void shrink(int i){
Person[] temp = new Person[arrayList.length - 1];
for (int index = 0; index < arrayList.length ; index++ ) {
if (index < i) {
temp[index] = arrayList[index];
}
else if (index == i){
removedPerson = arrayList[index];
temp[index] = arrayList[index + 1];
}
else{
temp[index - 1] = arrayList[index];
}
}
}
All of these files are in the same folder, so there shouldn't be an issue there. I am using terminal to compile by typing "javac FBArrayList.java". My compiler output looks like this:
FBArrayList.java:106: cannot find symbol
symbol : method expandInsert(int,FBList.Person)
location: class FBList.Person[]
arrayList.expandInsert(i, person);
^
FBArrayList.java:108: cannot find symbol
symbol : method insertAtEnd(int,FBList.Person)
location: class FBList.Person[]
arrayList.insertAtEnd(i, person);
^
FBArrayList.java:118: cannot find symbol
symbol : method shrink(int)
location: class FBList.Person[]
arrayList.shrink(i);
^
3 errors
Since Person
is an inner class, its name needs to be qualified with the name of the outer class:
protected void expandInsert(int i, FBList.Person person){
FBList.Person[] temp = new FBList.Person[arrayList.length * 2];
...
// and so on...
}
EDIT: Removed a suggestion to make class static
because the class is nested inside an interface. The suggestion would have been required for classes nested inside classes; for interfaces, static
is optional.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With