Array length property in Java - Practice Problems & Coding Challenges

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Challenge - 5 Problems

💻 code output

intermediate

What is the output of this Java code using array length?

Consider the following Java code snippet. What will be printed when it runs?

Java

public class Main {
    public static void main(String[] args) {
        int[] numbers = {5, 10, 15, 20, 25};
        System.out.println(numbers.length);
    }
}

A 6

B 5

C Compilation error

D 4

💻 code output

intermediate

What is the output when accessing length of a multidimensional array?

Look at this Java code. What will it print?

Java

public class Main {
    public static void main(String[] args) {
        int[][] matrix = new int[3][4];
        System.out.println(matrix.length);
    }
}

A 3

B 4

C 7

D Runtime error

💻 code output

advanced

What happens if you try to assign to the length property of an array?

What will happen when this Java code runs?

Java

public class Main {
    public static void main(String[] args) {
        int[] arr = {1, 2, 3};
        arr.length = 5;
        System.out.println(arr.length);
    }
}

A Runtime exception

B 5

C 3

D Compilation error

💻 code output

advanced

What is the output of this code accessing length of a null array?

What will this Java program print or do?

Java

public class Main {
    public static void main(String[] args) {
        int[] arr = null;
        System.out.println(arr.length);
    }
}

A 0

B Compilation error

C NullPointerException at runtime

D Prints 'null'

🧠 conceptual

expert

How many elements are in the array after this code runs?

What is the number of elements in the array 'data' after executing this code?

Java

public class Main {
    public static void main(String[] args) {
        int[] data = new int[10];
        data = new int[5];
        System.out.println(data.length);
    }
}

A 5

B 10

C 15

D Compilation error