Thread: ArrayList Errors

Please use "code" tags when you post code. [code]your code here[/code]

--- Update ---

"Cannot find symbol" is the compiler's way of saying that you have used a variable or method but the compiler can't find it defined anywhere.

Common causes are are typos where you mean one thing, but type another (leave letters out, get the case wrong etc). Basically, spelling matters and you will get a "Cannot find symbol" with every spelling mistake. With methods they have to have the same number and type of arguments that they are defined with. For example length() is a method that lists have which takes exactly zero arguments and that is how it has to be used. The following will all yield "Cannot find symbol": Length(), length, lenght(), length(3). So check every variable to see that you have declared it somewhere, and every method to see you have spelt it correctly and have used parentheses with the correct number of arguments.

The general idea of the code looks OK. But I have no idea why you have a null check in there. What is it supposed to do?

You have referred arrayStr[i] instead of arraylistStr[i]. So, compiler is saying spelling mistake.

Second thing before using collections/array/anything, first go through the usage, its syntax.
1. You cannot refer ArrayList's element as arraylistStr[i]. You must use get() to retrieve its element.
2. For checking the size of ArrayList, arraylistStr.size() is used not arraylistStr[i].length()

Originally Posted by mwardjava92

// I was asked to create an arraylist of strings, print out each element in
// the arraylist, the longest string and it's location. Below are the errors I am getting and the code.

Errors :

ArrayListString.java:27: cannot find symbol
symbol  : variable length
location: class java.util.ArrayList<java.lang.String>
		for(int i = 0; i < arraylistStr.length; i++)
		                               ^
ArrayListString.java:29: cannot find symbol
symbol  : variable arrayStr
location: class ArrayListString
			if(arrayStr[i] != null)   //int index = 0;
			   ^
ArrayListString.java:31: array required, but java.util.ArrayList<java.lang.String> found
				if(arraylistStr[i].length() > largest)
				               ^
ArrayListString.java:33: array required, but java.util.ArrayList<java.lang.String> found
					largest = arraylistStr[i].length();
					                      ^
ArrayListString.java:39: array required, but java.util.ArrayList<java.lang.String> found
		System.out.println("Element " + location + ", " + arraylistStr[largest]
		                                                              ^
5 errors

import java.util.ArrayList;
 
public class ArrayListString  
{
	public static void main(String args[])
	{
		ArrayList<String> arraylistStr = new ArrayList<String>();
 
		arraylistStr.add("Jim Bob");         // Add Strings to the first 3 elements
		arraylistStr.add("Bobby Jones");
		arraylistStr.add("Rob Styles");
 
		for(int count = 0; count <= arraylistStr.size(); count++)   // Print each element in arraylist			
		{
		 	System.out.println(arraylistStr.get(count));
		}
 
		int largest = 0, location = 0;   // Start largest off at 0
 
		for(int i = 0; i < arraylistStr.length; i++)
		{	
			if(arrayStr[i] != null)   //int index = 0;
			{
				if(arraylistStr[i].length() > largest)
				{
					largest = arraylistStr[i].length();
					location = i;
				}
			}
		}	
 
		System.out.println("Element " + location + ", " + arraylistStr[largest]
		+ ", is the largest and its size is " + largest);
	}
}