### What is the factorial in java

The factorial of a positive integer is the product of all positive integers less than it and itself.need to note that the factorial of 0 is 1.we use n! to represent the factorial of an integer number n.

In other words,n!=1x2x3x4x...xn.also can use recursion to defined a factorial as 0!=1, n!=(n-1)!xn.

### factorial using recursion in java

Let's write a java simple recursion program to get the factorial of given numbes from 0 to 10：

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public class MainClass { public static void main(String args[]) { for (int counter = 0; counter <= 10; counter++){ System.out.printf("%d! = %d\n", counter, factorial(counter)); } } public static long factorial(long number) { if (number <= 1) return 1; else return number * factorial(number - 1); } } |

output

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0! = 1 1! = 1 2! = 2 3! = 6 4! = 24 5! = 120 6! = 720 7! = 5040 8! = 40320 9! = 362880 10! = 3628800 |

### factorial using loop in java

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public class MainClass { public static void main(String args[]) { for (int counter = 0; counter <= 10; counter++){ System.out.printf("%d! = %d\n", counter, factorial(counter)); } } public static long factorial(long number) { int i,fact=1; for(i=1;i<=number;i++){ fact=fact*i; } return fact; } } |

output

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0! = 1 1! = 1 2! = 2 3! = 6 4! = 24 5! = 120 6! = 720 7! = 5040 8! = 40320 9! = 362880 10! = 3628800 |