Searching through a text file with Unity?

Questions & Answers
1

I’m teaching myself Unity over the summer as a side project, and decided a good way to start out was porting a word puzzle game I made previously over to the Unity engine. This has been successful so far, but I’ve run into a block I can’t find a way around, which is checking my dictionary to check if the words the player inputs are actually valid.

My dictionary is in simple .txt format, with each word listed in the following format:

aals
aardvark
aardwolf
aargh

The game was originally built in Python, where I used ReadLines() to load the dictionary into an array (set) so I could loop through it when searching for words. I can’t find any comparable way to do that with Unity however; text input/output functionality seems to be lacking with UnityScript.

Anyone know how I could check if a string variable exists within the dictionary?

2

Create your file as a .txt and put it in a Resources folder.

   import System.Collections.Generic;
   import System.Linq;

   ...

   var lex : Dictionary.<String, String>;

   function Awake() {
 
       var textAsset = Resources.Load("YourFileNameWithoutTheDotTxt", typeof(TextAsset))  as TextAsset;
       lex = textAsset.text.Split("

"[0]).ToDictionary(function(w){return w;});
}

   function Checkword(word : String) {
        return lex.ContainsKey(word);
   }
3

The by far fastest method to test whether a string is within an arbitrary large array/set/list of strings is by using a Hashtable, it will find objects in O(1) time.

Instead of storing your strings in a regular array or list, use:

myHashtable.Add(myWord,myWord);

or:

myHashTable[myWord]=myWord;

(the second “myWord” entry doesn’t really matter, as long as it’s non-null. You could also use it to store additional info)

To test whether a word exists use:

myHashtable.Contains(searchWord);

To retrieve the second parameter mentioned above use:

secondParameter=myHashtable[myWord];

Note you can also store different objects instead of just strings, even GameObject references and so on.

4

I had to combine some ideas from a couple users here in order to arrive at this correct line…

lex = textAsset.text.Split(" "[0]).ToDictionary(w => w);

User whydoidoit didn’t have the w => w

User Wolfram didn’t have the "
"[0]

Hope this helps others :slight_smile:

5

For those struggling with why ContainsKey() does not find your strings a match, it’s because Split() adds an empty character to the end of your strings/keys. To solve this issue, simply add a Remove() to your code:

lex = textAsset.text.Split("

"[0]).ToDictionary(w => w.Remove(w.Length - 1);

Also, if you want to read your .txt file from a path, you may want to put the file into the StreamingAssets folder. See details here