---
title: "Differentiate between 'out' and 'param' keywords in c# with example."  
description: "Differentiate between 'out' and 'param' keywords in c# with example."  
author: "Ethan Karla"  
published: 2021-08-25  
canonical: https://answers.mindstick.com/qa/93917/differentiate-between-out-and-param-keywords-in-c-sharp-with-example  
category: "programming"  
tags: ["c#", "java", "pythons"]  
reading_time: 3 minutes  

---

# Differentiate between 'out' and 'param' keywords in c# with example.

Differentiate between 'out' and '[param](https://answers.mindstick.com/qa/44567/who-launched-vidya-veerta-abhiyan-to-encourage-universities-to-display-portraits-of-param-veer-chakra-decorated-soldiers)' [keywords](https://www.mindstick.com/articles/12328/how-to-research-for-keywords) in c# with example.

## Answers

### Answer by Ravi Vishwakarma

Differentiate between 'out' and 'param' keywords in c# with example.

| **out keyword** | **params keyword** |
| --- | --- |
| It is not necessary to initialize parameters before pass data at the function call. | It is not necessary to initialize parameters before they pass out we can pass multiple values using this keyword. |
| It is necessary to initialize the value of a parameter before returning the value to the calling method. | It is not necessary to initialize the value of a parameter before returning to the calling method, only accessed. |
| The declaring of parameters through 'out' parameters is useful when a method returns multiple values. | it returns a single value. |
| When out keyword is used the data only passed in unidirectional. | When the params keyword is used the data is accessed only. |

Example

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ThreadDemo
{
    class OutAndParamsDemo
    {
        private int CountDigit(long value)
        {
            int count = 0;
            while (value != 0)
            {
                value /= 10;
                count++;
            }
            return count;
        }
        public void PrintNumberOfDigits(params long[] num)
        {
            foreach (long item in num)
            {
                Console.WriteLine($'{item} has {this.CountDigit(item)} digits.');
            }
        }
        public void GetValueByFunction(out int x, out int y)
        {
            x = 0;y = 0;
            x = 100;
        }
        public static void Main(string[] args)
        {
            OutAndParamsDemo outAnd = new OutAndParamsDemo();
            int n, p;
            // call the print number of digits function
            outAnd.PrintNumberOfDigits(751, 125, 485, 452196, 4152, 1450, 10101010101);
            // call the get value by function
            outAnd.GetValueByFunction(out n, out p);
            Console.WriteLine($'N : {n} P : {p}');
        }
    }
}
```

Output

![Differentiate between](https://answers.mindstick.com/questionanswer/5263b36d-dbd7-49c4-bbde-a3361bdec015/images/139f0864-b005-4f69-ad73-9d41cb29ff53.png)

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Original Source: https://answers.mindstick.com/qa/93917/differentiate-between-out-and-param-keywords-in-c-sharp-with-example

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