What is the error in this program?To display even numbers in arraylist?

Question

import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
public class Program
{
public static void main(String[] args) {
Scanner s=new Scanner (System .in);
int n=s.nextInt();
int [] a=new int [n];
ArrayList<Integer> evenlist=new ArrayList<Integer>();
for(int i=0;i<a.length;i++)
{
a[i]=s.nextInt();
if(a[i]%2==0)
{
evenlist.add(a[i]);

}
}
for(int i:evenlist)
{
System.out.println(i);
}
}
}

Answer 1

import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Program {
public static void main(String[] args) {
Scanner s=new Scanner (System .in);
int n = s.nextInt();

//int [] a=new int [n];

List<Integer> evenlist = new ArrayList<Integer>();

for(int i = 0; i < n; i++) {
int a = s.nextInt();

if(a % 2 == 0)
evenlist.add(a);
}

for(int i : evenlist)
System.out.println(i);
}
}

Take input like:

5
1
2
3
4
5

Answer 2

The code you've provided seems correct for the most part. However, there is one issue in your code: you are not populating the array `a` with input values from the user before checking for even numbers. To fix this issue, you need to change this line:

```java
int [] a=new int [n];
```

to:

```java
int[] a = new int[n];
for (int i = 0; i < n; i++) {
a[i] = s.nextInt();
}
```

Here's the updated code with the correction:

```java
import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;

public class Program {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int n = s.nextInt();
int[] a = new int[n];
ArrayList<Integer> evenlist = new ArrayList<Integer>();

for (int i = 0; i < a.length; i++) {
a[i] = s.nextInt();
if (a[i] % 2 == 0) {
evenlist.add(a[i]);
}
}

for (int i : evenlist) {
System.out.println(i);
}
}

Answer 3

}

With this change, your program should now correctly read input values into the array a and display even numbers in the evenlist ArrayList.

Answer 4

There's some redundant code, but it works for me. What is the problem in your mind?

Answer 5

It doesn't display anything

Answer 6

It does for me. You're making a mistake somewhere else.

Answer 7

Pls send code

Answer 8

Is this code correct

Answer 9

I did not change the code. Your code works.

As a side note though, if you only want to print a list of numbers, you don't need both a list and an array. Use only one.