Calling a constructor with object array

You can do one of two things:

1.Create a temporary object by calling the constructor and then adding that object in the array:

Student temp= new Student(x,y,z); arr[i]=temp; 

2.Directly instantiate a new object and add it in the array like this:

arr[i]=new Student(x,y,z); 

Both methods will work fine, but it is recommended to use method 2 because you should not allocate memory to a temp object when clearly you can achieve the goals without doing so

Instead of:

arr[i]=arr.Student(x,y,z);

Do:

arr[i]=new Student(x,y,z);

Why? Because, Each object in the array is an instance of Student class

Your constructor is declared wrongly. this is always used to refer to the instance variable. Change your constructor to this:

public class Student { int id; String name; double marks; public Student(int id, String name, double marks) { this.id = id; this.name = name; this.marks = marks; } } public class Solution { public static void main(String[],args) { Scanner sc = new Scanner(System.in); int n=sc.nextInt(); Student[] arr=new Student[n]; for(int i=0;i<n;i++) { int x =sc.nextInt(); String y=sc.nextLine(); double z=sc.nextDouble(); arr[i]= new Student(x,y,z); //no need to create an object for arr } } } 

Because your constructor is wrong.

public class Student { int id; String name; double marks; public Student(int id, String name, double marks) { this.id = id; this.name = name; this.marks = marks; } }