Regarding Java ArrayList program

[Sumit Yadav]

Hello all, I am new here and i am learning java from the scratch. I was writing a java code about replace the second element of a ArrayList with the specified element. Here is my Code:

 

import java.util.ArrayList;
  public class program {
    public static void main(String[] args){
  ArrayList<String>  color = new ArrayList<String>();

  color.add("Red");
  color.add("Green");

  System.out.println("Original array list: " + color);
  String color = "White";
  color.set(1,new_color);

  int num=color.size();
  System.out.println("Replace second element with 'color'."); 
  for(int i=0;i<num;i++)
  System.out.println(color.get(i));
  }
}

 While run the code it shows an error. i am not understand how to resolve this, can any one please help me on this, I was taking reference from here

[jontomonta]

Yes, there are a few errors in the code. Here are the issues I found:

1. The variable new_color is not defined. It seems like you meant to use the variable color instead of new_color when calling the set method on the color ArrayList.
2. The variable color is already defined as an ArrayList of Strings. You cannot redefine it as a String on the line String color = "White";.
3. The set method of an ArrayList takes two arguments: the index of the element to replace and the new element. In this case, you should replace color.set(1,new_color); with color.set(1, color);.

Here is the corrected version of the code:

import java.util.ArrayList;
public class program {
  public static void main(String[] args){
    ArrayList<String> color = new ArrayList<String>();

    color.add("Red");
    color.add("Green");

    System.out.println("Original array list: " + color);
    String newColor = "White";
    color.set(1,newColor);

    int num=color.size();
    System.out.println("Replace second element with 'White'."); 
    for(int i=0;i<num;i++)
      System.out.println(color.get(i));
  }
}