Ruby program to find factorial of a given number

Given/Input an integer number and find the factorial in Ruby.

We can find the factorial of a number n by multiplying it with its predecessors up to 1. For example, if we have to find factorial of 5, the equation will look like:

    5! = 5*4*3*2*1, which will be equal to 120.

For implementing the above logic, we can put the variable num in the Boolean condition and after initialising a variable fact, we can simply multiply fact with a variable i which is initialised by 1. Increase i with every iteration and the loop will be terminated when i will become equal to num.

Methods used:

• puts: put string method is used for printing message.
• gets: get string method is used for taking input from the user.
• .to_i: It is converting user inputted string into integer value type.

Operators used:

• ==: Equal to operator. Used to check the equality of left hand value with the right hand one.
• =: Assignment operator. Used to assign a value to the variables.
• <=: Less than or equal to operator. Basically used for comparison.
• *: Multiplication Arithmetic Operator used for the multiplication.
• +: Addition Arithmetic Operator. Used for adding two variables.

Variables used:

• num: Used to store the value given by the user.
• fact: Used to store the final factorial.
• i: It is acting as a loop variable.