Java for loop error

Question

I am trying to get user input for sortValues[] array using the for statement (enter character 1, enter character 2, etc).

However, when I execute this, the program will not allow me to enter for character 2, instead skipping directly to character 3, as seen below.

enter image description here

How to resolve this? The code is included below.

thanks!

static public void s_1d_char () {
            int counter=0;
            int x=0;
            c.print("How many characters? ");
            counter = readInt();

            char[] sortValues = new char[counter+1];

            for (x=1;x<=counter;x++) {
                    System.out.println("Enter character "+(x)+":");
                sortValues[x] = readChar();
            }
    }

readChar implementation (this is from a library):

public synchronized char readChar ()
{
char result, ch;

if (ungotChar != EMPTY_BUFFER)
{
    result = (char) ungotChar;
    ungotChar = EMPTY_BUFFER;
    return (result);
}

if (lineBufferHead != lineBufferTail)
{
    result = lineBuffer [lineBufferTail];
    lineBufferTail = (lineBufferTail + 1) % lineBuffer.length;
    return (result);
}

startRow = currentRow;
startCol = currentCol;
if (currentRow > maxRow)
{
    startRow++;
    currentCol = 1;
}

// Turn cursor on if necessary
consoleCanvas.setCursorVisible (true);

// Wait for a character to be entered
while (true)
{
    ch = getChar ();

    if (ch == '\n')
    {
    clearToEOL = false;
    if (echoOn)
        print ("\n");
    clearToEOL = true;
    lineBuffer [lineBufferHead] = '\n';
    lineBufferHead = (lineBufferHead + 1) % lineBuffer.length;
    break;
    }
    if (ch == '\b')
    {
    if (lineBufferHead == lineBufferTail)
    {
        consoleCanvas.invertScreen ();
    }
    else
    {
        int chToErase;

        lineBufferHead = (lineBufferHead + lineBuffer.length - 1) % lineBuffer.length;
        chToErase = lineBuffer [lineBufferHead];
        if (echoOn)
        {
        if (chToErase != '\t')
        {
            erasePreviousChar ();
        }
        else
        {
            int cnt;
            eraseLineOfInput ();
            cnt = lineBufferTail;
            while (cnt != lineBufferHead)
            {
            print (lineBuffer [cnt]);
            cnt = (cnt + 1) % lineBuffer.length;
            }
        }
        }
    }
    } // if backspace
    else if (ch == '\025')
    {
    if (echoOn)
    {
        eraseLineOfInput ();
    }
    lineBufferHead = lineBufferTail;
    }
    else
    {
    if (echoOn)
    {
        print (ch);
    }
    lineBuffer [lineBufferHead] = ch;
    lineBufferHead = (lineBufferHead + 1) % lineBuffer.length;
    }
} // while

result = lineBuffer [lineBufferTail];
lineBufferTail = (lineBufferTail + 1) % lineBuffer.length;

// Turn cursor on if necessary
consoleCanvas.setCursorVisible (false);

return (result);
}

I don't know if it is the case, which is why im' making comments and not answers, but you can check by just not pressing enter between chars — Sam I am says Reinstate Monica
– Sam I am says Reinstate Monica, Commented Jul 10, 2012 at 21:45
If you use a BufferedInputStream to wrap your input, you have a handy readLine() method. — SJuan76
– SJuan76, Commented Jul 10, 2012 at 21:46

Chris Dargis · Accepted Answer · 2012-07-11 00:18:03Z

1

I recommend getting user input with a scanner:

import java.util.Scanner;

// ...
int counter = 0;

System.out.println("How many characters?");
Scanner keyboard = new Scanner(System.in);
counter = keyboard.nextInt();

char[] sortValues = new char[counter+1];

// Start your index variable off at 0
for (int x = 0; x < counter; x++) { 
  System.out.println("Enter character "+(x)+":");
  keyboard = new Scanner(System.in);
  String line = keyboard.nextLine();
  sortValues[x] = line.charAt(0);
}

This will capture the first character of the line. If the user enters more than one character, the program will read only the first. Also, you should really start your index variable x off at 0, considering arrays are 0-based indexed.

edited Jul 11, 2012 at 0:18

answered Jul 10, 2012 at 22:15

Chris Dargis

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2 Comments

01jayss Over a year ago

thanks for your response. I have implemented your code, however, the program now stops after "How many characters" (it does not display Enter character, etc)...do you know the solution?

Chris Dargis Over a year ago

@01jayss: I updated the code snippet with a working solution.

Community · Accepted Answer · 2017-05-23 10:30:28Z

1

instead of readChar() try:

sortValues[x] = Integer.parseInt(System.console().readLine());

How to read integer value from the standard input in Java

edited May 23, 2017 at 10:30

CommunityBot

11 silver badge

answered Jul 10, 2012 at 21:45

J Max

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4 Comments

01jayss Over a year ago

this only works for getting an integer... im trying to get a "char" value

Pshemo Over a year ago

@01jayss try maybe char c=System.console().readLine().charAt(0)

Roddy of the Frozen Peas Over a year ago

A char can be represented by an int. See docs. It's a 16-bit int, essentially, whereas the int data type is 32-bit.

ardent Over a year ago

@01jayss, what Roddy said, so long as you store it in a char (and maybe give it a cast), Java will automatically display it as a char.

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