Thread: String Arrays []

Hi guys,

As part of a Research project in cryptography i am doing a very basic model of a dictionary attack. This is not an actual dictionary attack just to help explain things in my essay.

So here is what Im trying to do:

I have made a very small dictionary using String Array that contains just around 50 words or so.
I have Created Scanner object to read in user input.

Here is what I have so far:

String[] words = new String[] { "animal", "anthony", "bear", "bright", 
            "cat", "cities", "control", "copper", "country", "degree", "driving",
            "electric", "earth", "eggs", "expert", "family", "female", "flying",
            "friend", "fuit", "guessing", "german", "gold", "green", "happy", 
            "harbour", "heart", "history", "horse", "insect", "interest", "internet",
            "island", "jelly", "journey", "judge", "kettle", "kiss", "language",
            "laugh", "letter", "loud", "machine", "male", "manager", "market",
            "married", "measure", "monkey", "noise", "nose", "number", "officer",
            "opinion", "other", "orange", "paint", "parcel", "potato", "quick",
            "quiet", "reading", "record", "snow", "school", "science", "ship",
            "teacher", "thunder", "trousers", "value", "voice", "waiting", "walking",
            "woman", "yellow", "zebra"};
 
        // Create a new Scanner Object called scan
        Scanner scan = new Scanner(System.in);
 
        // Print out a request and display to the User
        // & Read In User Input using the Scanner Object
        System.out.println("Enter a common word: ");
        scan.nextLine();

Right... now what I am trying to do is..... when the user enters a random common word, the program searches the String Array and prints out either ''matching word'' or ''non matching word''.

So how do i go about getting the program to search the words in the string array.

I think an if statement is used no ?

i.e. if ('word entered by user' = 'one of the values in the string array')

then .....


Something like that ? But im not really sure.

Thanks for your help.

To determine if an item is in an array you will need to look at each element in the array, usually done in a loop.
You should look at using one of the collection classes to hold the words. Many have a contains() method that will say if an item is in the container. The HashSet class might work

String input = new Scanner(System.in).next(); 
boolean contains = false;
for(String w : words){
if(input.equalsIgnoreCase(w)){
contains = true;
break;
}
}
if(contains){
System.out.println(String.format("Array contains %s", input));
}else{
System.out.println(String.format("Array does not contain %s", input));
}

If you need to know what index that word is at, just use a normal for loop.

If what you're interested in is an exact match, you can sort your array with Arrays.sort and search it with Arrays.binarySearch. Check the API docs for java.util.Arrays.

Originally Posted by Norm

To determine if an item is in an array you will need to look at each element in the array, usually done in a loop.
You should look at using one of the collection classes to hold the words. Many have a contains() method that will say if an item is in the container. The HashSet class might work

Hi.

This sounds like the best method.

So i need to do a if (the string array contains 'the word the user entered')

then ....... System.out.print("found matching word");

else ... ("no match found");

But how do i actually implement this?

I am really stuck. Please help.

regards.

Which technique do you want to use? post#3 shows one way.

Oh Right apologies. I quickly skim read the replies. Didnt realise Post 3 posted code.

I will now try this.....

Yep that works fine. Just what I wanted.

thanks alot.