Making arrays by reading user input

[apfroggy0408]

Arrays are definitely one of my weak points, and I'm confused as crap as to how to make an array of a string input.

[sukatoa]

What do you mean? every input shall be stored in and array?

Correct me if im too far from your point

[apfroggy0408]

From what I get from your question is yes. Maybe this will help.

Code:

//call for input
Scanner input = new Scanner(System.in);
System.out.println("Enter sentence: ");
String sent = input.nextLine;

// How do I get sent into an array?

[Zosden]

I would use a vector here but you should just do my
String[] myString = new String[What Ever Size];
myString[i] = input.getNextLine();

[Eranga]

But here defining the array size can be make an error. ArrayList may be a good choice.

[sukatoa]

String array[] = {"Me","You","Them","Us","Other","They"};

Can you access every element of an array?

If not, try to have an experiment....

String s = array[3];
int len = array.length;
String s1 = array[7];
String s2 = array[-1];
Try to observe the output....

By storing an input to an array,
array[0] = "Chupacabras";
array[1] = "Rasta";
array[2] = true;
array[3] = false;
Try to observe what happens now when you seek again the value of every element of the array.... ( showing it again ).....

But it is important to read a tutorials about arrays....
There are more and understandable explanations there....

[apfroggy0408]

I'm pretty familiar with making an array with hardcoded information. But what's confusing me is the array with user input.

Code:

Scanner input = new Scanner(System.in);
    		System.out.println("Enter String to use: ");
    		String list = input.nextLine();
    		String trimmedword = list.trim();
    		System.out.println("Enter Index: ");
    		int index = input.nextInt();

Is what I have to start with.

I'm using the trim because I need to able to manipulate this array with the index choice. So I need to turn that trimmed string into an array.

[Eranga]

Now you got the answer right. Is that not clear what Zosden says?

[apfroggy0408]

Would that work using my trim variable? I'm kind of confused by it.

[Eranga]

Not to worry with trim(), if a white space is there or no, in an Array it not a case.

[apfroggy0408]

How would I go about using ArrayList?

would it be like

Code:

ArrayList[] myString = new ArrayList[];
System.out.println("Enter sentence: ");
myString[] = input.getNextLine;

[Eranga]

Defining array list is wrong there.

Code:

        ArrayList al = new ArrayList();
        Scanner input = new Scanner(System.in);
        
        System.out.println("Enter the string: ");
        String str = input.nextLine().trim();
        
        System.out.println("Enter an index: ");
        int index = input.nextInt();
        
        al.add(index, str);

Loop this to handle for any number of inputs.

[apfroggy0408]

I'm guessing add adds the string and index to the array correct?

[apfroggy0408]

--------------------Configuration: <Default>--------------------
Note: G:\AP Comp. Sci\Labs\p499proj12l2.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.


eh...?

[Eranga]

If you want to do it with an array, do it as follows.

Code:

        String[] mm = new String[10];
        Scanner input = new Scanner(System.in);
        
        System.out.println("Enter the string: ");
        String str = input.nextLine().trim();
        
        System.out.println("Enter an index: ");
        int index = input.nextInt();
        
        mm[index] = str;

Issue is there, defining the size of the array. According to my code, you can't exceed 10 for index.

ArrayList is something different. Size is grow depending on your insertion into the list.

[Eranga]

Quote:

Originally Posted by apfroggy0408

--------------------Configuration: <Default>--------------------
Note: G:\AP Comp. Sci\Labs\p499proj12l2.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.


eh...?

Ah, it's the warning that ArrayList is not defined as an expandable array. It's not a big case for the simple processing, like we do here.

If you want to avoid it, change the ArrayList definition as follows.

Code:

ArrayList<String> al = new ArrayList<String>();

[apfroggy0408]

Oh, alright. Now the question I have now is why do you have index placed in []? I'm going to be using the inputted index to find a certain spot in the array. As in index 2 in shoe would be h.

[Eranga]

Quote:

Originally Posted by apfroggy0408

Oh, alright. Now the question I have now is why do you have index placed in []?

That's the inbuilt pattern pal.

[apfroggy0408]

So, haven't been able to get back to this program 'til now, and I'm still lost.

I have the code

Code:

ArrayList<String> mm = new ArrayList<String>();
        	Scanner input = new Scanner(System.in);
        
       	 	System.out.println("Enter the string: ");
        	String str = input.nextLine().trim();
        
        	System.out.println("Enter an index: ");
        	int index = input.nextInt();
        
        	mm[index] = str;
        	System.out.println(mm);
        	System.out.println(index);

But I can't get the array to show.

[Eranga]

You want to display all array elements? Loop it.