Disable a string in array to prevent duplicates

Question

I have this application where i have to insert the same string in a textbox as the one in the array. The strings come by in a label, for every answer it will go to a random word/string that is in the array.

My question is: Is there any way to delete or disable a word/string in the array so I don't get any duplicates?

string[] arrProvincies = File.ReadAllLines(@"provincies.txt");

int counter = 0;
string Array = "";

string Array = arrProvincies[counter].ToString();
lblProvincie.Text = Array;
counter = rnd.Next(0, 12);

Just call `var provinces=arrProvincies.Distinct()` to get distinct entries — Panagiotis Kanavos, Sep 12 '16 at 12:57
`Prevent duplicates` is not the same as `random selection without repetition`. What do you actually want? — Panagiotis Kanavos, Sep 12 '16 at 12:59
@Tuur you are looking for *shuffling*, generating a random order from the original list. — Panagiotis Kanavos, Sep 12 '16 at 13:03

Thomas Ayoub · Accepted Answer · 2016-09-12T13:52:27.780

2

You can use a Queue:

Queue<string> arrProvincies = new Queue<string>(File.ReadAllLines(@"provincies.txt"));

And use it with lblProvincie.Text = arrProvincies.Dequeue();

Thus you'll be sure to have no duplicate since your remove the entry when you use it.

If you need shuffling:

Queue<string> arrProvincies = new Queue<string>(File.ReadAllLines(@"provincies.txt").OrderBy(o => Guid.NewGuid()));

edited Sep 12 '16 at 13:52

answered Sep 12 '16 at 12:57

Thomas Ayoub

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The OP is trying to retrieve entries randomly. The lines should be shuffled before loading in the queue – Panagiotis Kanavos Sep 12 '16 at 13:00
@PanagiotisKanavos true, added info. – Thomas Ayoub Sep 12 '16 at 13:01
@Tuur replace your declaration of `arrProcincies` with mine – Thomas Ayoub Sep 12 '16 at 13:04
Only problem is, it will go by the same order everytime, it might be shuffled, but that stays the same everytime – Gekkehond Sep 12 '16 at 13:40
1

I think you want `Guid.NewGuid()` instead of `new Guid()`, as that will give you random Guids and not just `Guid.Empty` – Wyatt Earp Sep 12 '16 at 13:46
How would queuing and dequeueing prevent duplicates? It wouldn't, would it? – Cetin Basoz Sep 12 '16 at 20:53
@cetinbasoz it ensure that the same string is not used twice since it's removed from the queue. Of course, this needs the source file to not contains duplicate content – Thomas Ayoub Sep 13 '16 at 06:30

score 1 · Answer 2 · answered Sep 12 '16 at 13:10

string[] arrProvincies = File.ReadAllLines(@"provincies.txt");

var randomProvincies = arrProvincies.Distinct().OrderBy(i => Guid.NewGuid());

randomProvincies would be the distinct values ordered randomly (I couldn't understand the part where it says you would insert the same string in a textbox).

Disable a string in array to prevent duplicates

2 Answers2