29. Write a program in Java to compute and display factorial of numbers up to a number entered via the Scanner class. The output should look like as shown below when 7 is input.

Enter a number: 7
1! (=1) = 1
2! (= 1 x 2) = 2
3! (= 1 x 2 x 3) = 6
4! (= 1 x 2 x 3 x 4) = 24
5! (= 1 x 2 x 3 x 4 x 5) = 120
6! (= 1 x 2 x 3 x 4 x 5 x 6) = 720
7! (= 1 x 2 x 3 x 4 x 5 x 6 x 7) = 5040

Program Title: Display Factorials up to N

Java

import java.util.Scanner;
 
public class FactorialUpToN {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        System.out.print("Enter a number: ");
        int n = sc.nextInt();
 
        for (int i = 1; i <= n; i++) {
            long factorial = 1;
            String expression = "";
 
            for (int j = 1; j <= i; j++) {
                factorial *= j;
                expression += j;
                if (j < i) {
                    expression += " x ";
                }
            }
 
            System.out.println(i + "! (=" + expression + ") = " + factorial);
        }
 
        sc.close();
    }
}

Output

Sample Input / Output
Enter a number: 7
1! (=1) = 1
2! (=1 x 2) = 2
3! (=1 x 2 x 3) = 6
4! (=1 x 2 x 3 x 4) = 24
5! (=1 x 2 x 3 x 4 x 5) = 120
6! (=1 x 2 x 3 x 4 x 5 x 6) = 720
7! (=1 x 2 x 3 x 4 x 5 x 6 x 7) = 5040

📝 Explanation

Outer loop runs from 1 to n → computes factorial for each number.
Inner loop:

Multiplies numbers to get factorial.
Builds a string expression to show the factorial multiplication.

Prints the factorial with the format:

i! (= 1 x 2 x ... x i) = factorial