reversing text from input file using linq

Question

I would like to reverse each word from input.txt using c# and linq and display the output text, so far i have a code that inputs the word and reverses it.

using System;
using System.Text;
using System.Linq; 

namespace program
{
    class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("String:");
            string name = Console.ReadLine();

            string output = new string(name.ToCharArray().Reverse().ToArray());

            Console.WriteLine(output);
        }
    }
}

Could you please show an example input and output? Do you want to reverse every string a file? — Soner Gönül, Mar 17 '14 at 12:47
possible duplicate of [Easy way to reverse each word in a sentence](http://stackoverflow.com/questions/5391198/easy-way-to-reverse-each-word-in-a-sentence) — Soner Gönül, Mar 17 '14 at 12:48
Could you clarify whether you want to reverse the whole thing or pieces within it, i.e. a string or the word(s) in a string? If the string is "one two three" would the correct result be "eerht owt eno" or "three two one"? — Rick Davin, Mar 17 '14 at 12:50
You're converting the entire string to an char array. Try splitting it into an array of strings (words delimited by blanks), then reverse that string. — Rick Davin, Mar 17 '14 at 12:51

score 4 · Accepted Answer · edited May 23 '17 at 12:21

4

string input = "I love programming";
string output = String.Join(" ",
                   input.Split().Select(w => new String(w.Reverse().ToArray())));
// I evol gnimmargorp

Reading file is simple:

string input = File.ReadAllText("input.txt");

You can also move word reversing into separate method. That will allow you to change algorithm of string reversing without touching other logic:

private static string GetReversedString(string s)
{
    return new String(s.Reverse().ToArray());
}

And getting reversed output will look like:

string output = String.Join(" ", input.Split().Select(GetReversedString));

If lines should be preserved:

string output = 
    String.Join(Environment.NewLine, 
                File.ReadLines().Select(l => 
                       String.Join(" ", l.Split().Select(GetReversedString))));

edited May 23 '17 at 12:21

Community

1
1

answered Mar 17 '14 at 12:48

Sergey Berezovskiy

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@TimSchmelter agree, if file has words in lines and lines should be preserved and there is more than one word on each line, then splitting/joining should require additional work – Sergey Berezovskiy Mar 17 '14 at 13:05
Thanks, just an extra question, how can i write output to output.txt ? – user3215507 Mar 17 '14 at 13:07
@user3215507 use `File.WriteAllText("output.txt", output)` – Sergey Berezovskiy Mar 17 '14 at 13:10

score 0 · Answer 2 · answered Mar 17 '14 at 12:50

0

The reversal code could be refactored in an extension method for String; Next, a text file should be opened, the lines splitted to single words and the words mapped reversely to the console.

answered Mar 17 '14 at 12:50

Codor

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reversing text from input file using linq

2 Answers2