Multi-Dimentional Array: I can't seem to print out the variables please help.

[XxClouDxX]

import java.util.Scanner;

public class Scheduler {

public static final String[] time = { "7:30", "8:30", "9:30", "10:30",
"11:30", "1:00", "2:00", "3:00", "4:00" };

public static void main(String[] args) {
Scanner kb = new Scanner(System.in);
String input;
String[] temp;
String classTime;
String day;
String course;
String[][] sked;
int row = 0;
int col = 0;

sked = new String[9][6];

do {
System.out
.println("Please input the Course,Day/s, and Time accordingly.");
input = kb.nextLine();
if (input.isEmpty()) {
break;
}

temp = input.split(",");
course = temp[0].toUpperCase();
classTime = temp[2];
day = temp[1].toUpperCase();

if (classTime.matches("[0-9]{1,2}:[0-9]{2}")) {
row = " 7:30 8:30 9:3010:3011:30 1:00 2:00 3:00 4:00"
.indexOf(classTime) / 5;

System.out.println(row);

}

// -------------------------days
// prototype----------------------------------
/*
* if(day.matches ("[MTWHFS]{1,6}")){ for (int i = 0; i <
* day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
* System.out.println(i); } }else{ System.out.println("Error!"); }
*/

/*
* if (day.matches("[MTWHFS]{1,6}")) { for (int i = 0; i <
* day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
* System.out.println(i); if (sked == null) { sked [row][col] =
* course; } else { System.out.println("class is overlapping"); } }
* }
*/
// ---------------------------end days prototype...these are
// failures...------

if (day.matches("[MTWHFS]{1,6}")) {
for (int i = 0; i < day.length(); i++) {
col = "MTWHFS".indexOf(day.charAt(i));
System.out.println(col);
}
} else {
System.out.println("Error!");
}

} while (true);

// ---------------------printout
// prototypes.------------------------------------
/*
*
* System.out.println(); System.out.println(
* "\t\tMonday Tuesday Wednesday Thursday Friday Saturday"
* ); for (int r=0;r<time.length;r++){ System.out.print(time[r] + "\t");
* for (int c=0;c<sked[0].length;c++){ if ( sked[r][c] == null ){
* System.out.print(""); } else { System.out.printf("%-2s",sked[r][c] +
* "\t\t"); } } System.out.println(); }
*/
/*
* System.out.printf("%-5s%10s%10s%10s%10s%10s%10s%n","","M","T","W","H",
* "F","S"); for (int c = 0; c < sked[0].length; c++) {
* System.out.printf("%-5s", time[c]);
*
* for (int r = 0; r < sked.length; r++) { System.out.printf("%10s",
* sked[r][c]); }
*
* System.out.println(); }
*/
System.out
.println("\t\tMonday Tuesday Wednesday Thursday Friday Saturday");
for (int r = 0; r < time.length; r++) { // top to bottom
System.out.println(time[r] + "\t");
for (int c = 0; c < sked[0].length; c++) { // left to right
if (sked[r][c] == null) {
System.out.print("");
} else {
System.out.printf("%-2s", sked[r][c] + "\t\t");
}
// array elements accessed as table[row][col] 
}
}

}
}


what's wrong with this piece of code? The things I input won't print out. please help

newbie here.

[javapenguin]

import java.util.Scanner;
 
public class Scheduler {
 
public static final String[] time = { "7:30", "8:30", "9:30", "10:30",
"11:30", "1:00", "2:00", "3:00", "4:00" };
 
public static void main(String[] args) {
Scanner kb = new Scanner(System.in);
String input;
String[] temp;
String classTime;
String day;
String course;
String[][] sked;
int row = 0;
int col = 0;
 
sked = new String[9][6];
 
do {
System.out
.println("Please input the Course,Day/s, and Time accordingly.");
input = kb.nextLine();
if (input.isEmpty()) {
break;
}
 
temp = input.split(",");
course = temp[0].toUpperCase();
classTime = temp[2];
day = temp[1].toUpperCase();
 
if (classTime.matches("[0-9]{1,2}:[0-9]{2}")) {
row = " 7:30 8:30 9:3010:3011:30 1:00 2:00 3:00 4:00"
.indexOf(classTime) / 5;
 
System.out.println(row);
 
}
 
// -------------------------days
// prototype----------------------------------
/*
* if(day.matches ("[MTWHFS]{1,6}")){ for (int i = 0; i <
* day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
* System.out.println(i); } }else{ System.out.println("Error!"); }
*/
 
/*
* if (day.matches("[MTWHFS]{1,6}")) { for (int i = 0; i <
* day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
* System.out.println(i); if (sked == null) { sked [row][col] =
* course; } else { System.out.println("class is overlapping"); } }
* }
*/
// ---------------------------end days prototype...these are
// failures...------
 
if (day.matches("[MTWHFS]{1,6}")) {
for (int i = 0; i < day.length(); i++) {
col = "MTWHFS".indexOf(day.charAt(i));
System.out.println(col);
}
} else {
System.out.println("Error!");
}
 
} while (true);
 
// ---------------------printout
// prototypes.------------------------------------
/*
*
* System.out.println(); System.out.println(
* "\t\tMonday Tuesday Wednesday Thursday Friday Saturday"
* ); for (int r=0;r<time.length;r++){ System.out.print(time[r] + "\t");
* for (int c=0;c<sked[0].length;c++){ if ( sked[r][c] == null ){
* System.out.print(""); } else { System.out.printf("%-2s",sked[r][c] +
* "\t\t"); } } System.out.println(); }
*/
/*
* System.out.printf("%-5s%10s%10s%10s%10s%10s%10s%n","","M","T","W","H",
* "F","S"); for (int c = 0; c < sked[0].length; c++) {
* System.out.printf("%-5s", time[c]);
*
* for (int r = 0; r < sked.length; r++) { System.out.printf("%10s",
* sked[r][c]); }
*
* System.out.println(); }
*/
System.out
.println("\t\tMonday Tuesday Wednesday Thursday Friday Saturday");
for (int r = 0; r < time.length; r++) { // top to bottom
System.out.println(time[r] + "\t");
for (int c = 0; c < sked[0].length; c++) { // left to right
if (sked[r][c] == null) {
System.out.print("");
} else {
System.out.printf("%-2s", sked[r][c] + "\t\t");
}
// array elements accessed as table[row][col] 
}
}
 
}
}

I've put it in coding format so I can read it better.

I did notice something odd.

It seems you've got a do.....while(true) loop that of course will never end as long as the program runs.

Hence it'll never get to the printing out part.

[XxClouDxX]

Any good suggestions then? This program was supposed to print out what index the day and the time is, and then print a table of it. The purpose of the do-while loop there is for the user to input as many subjects, and when the user, inputs nothing, the table prints out.

my expected output:

Please input the Course,Day/s, and Time accordingly:
IT121,F,7:30

Please input the Course,Days/s and Time accordingly:
PE2,S,9:30

Please input the Course,Day/s and Time accordingly:


        Monday           Tuesday             Wednesday            Thursday           Friday           Saturday


7:30                                                                                  IT121
8:30
9:30                                                                                                   PE2
10:30
11:30
1:00
2:00
3:00
4:00 

[javapenguin]

Well, did you ever initialize that 2D String array? I mean the values. Unless it's a primitive type, when you refer to the values at the indexes, you'll be getting Null Pointer Exceptions even if you did get to the printing out part.

Also, that break statement stopped it from being an infinite loop, though you could have put

do.....while(!input.isEmpty()) instead and left out the break statement.

I was able to get something similar to what you have above though it's not printing out the class like your example above is.

As for that, I think it likely you're not setting those values. I'm assuming that's what your sked array is being used for.

On second thought, keep the break in there. Otherwise it'll be throwing Index Out of Bounds Exceptions I think as it will be referring to null input.

[javapenguin]

I think maybe it's because it has sked[0].length in the for loop perhaps but I was able to, with the code below:

   import java.util.Scanner;
 
   public class Scheduler {
 
      public static final String[] time = { "7:30", "8:30", "9:30", "10:30",
         "11:30", "1:00", "2:00", "3:00", "4:00" };
 
      public static void main(String[] args) {
         Scanner kb = new Scanner(System.in);
         String input = "";
         String[] temp;
         String classTime = "";
         String day = "";
         String course = "";
         String[][] sked;
         int row = 0;
         int col = 0;
 
         sked = new String[9][6];
         for (int i =0; i < sked.length; i++)
         {
            for (int j =0; j < sked[i].length; j++)
               sked[i][j] = "";
         }
 
 
         do {
 
            System.out
               .println("Please input the Course,Day/s, and Time accordingly.");
            input = kb.nextLine();
            if (input.isEmpty()) {
               break;
            }
 
            temp = input.split(",");
            course = temp[0].toUpperCase();
 
            day = temp[1].toUpperCase();
 
            if (classTime.matches("[0-9]{1,2}:[0-9]{2}")) {
               row = " 7:30 8:30 9:3010:3011:30 1:00 2:00 3:00 4:00"
                  .indexOf(classTime) / 5;
 
               System.out.println(row);
 
            }
 
         // -------------------------days
         // prototype----------------------------------
         /*
         * if(day.matches ("[MTWHFS]{1,6}")){ for (int i = 0; i <
         * day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
         * System.out.println(i); } }else{ System.out.println("Error!"); }
         */
 
         /*
         * if (day.matches("[MTWHFS]{1,6}")) { for (int i = 0; i <
         * day.length(); i++) { col = "MTWHFS".indexOf(day.charAt(i));
         * System.out.println(i); if (sked == null) { sked [row][col] =
         * course; } else { System.out.println("class is overlapping"); } }
         * }
         */
         // ---------------------------end days prototype...these are
         // failures...------
 
            if (day.matches("[MTWHFS]{1,6}")) {
               for (int i = 0; i < day.length(); i++) {
                  col = "MTWHFS".indexOf(day.charAt(i));
                  System.out.println(col);
                  sked[row][col] = course;
               }
            } 
            else {
               System.out.println("Error!");
            }
 
         } while (true);
 
      // ---------------------printout
      // prototypes.------------------------------------
      /*
      *
      * System.out.println(); System.out.println(
      * "\t\tMonday Tuesday Wednesday Thursday Friday Saturday"
      * ); for (int r=0;r<time.length;r++){ System.out.print(time[r] + "\t");
      * for (int c=0;c<sked[0].length;c++){ if ( sked[r][c] == null ){
      * System.out.print(""); } else { System.out.printf("%-2s",sked[r][c] +
      * "\t\t"); } } System.out.println(); }
      */
      /*
      * System.out.printf("%-5s%10s%10s%10s%10s%10s%10s%n","","M","T","W","H",
      * "F","S"); for (int c = 0; c < sked[0].length; c++) {
      * System.out.printf("%-5s", time[c]);
      *
      * for (int r = 0; r < sked.length; r++) { System.out.printf("%10s",
      * sked[r][c]); }
      *
      * System.out.println(); }
      */
         System.out
            .println("\t\tMonday Tuesday Wednesday Thursday Friday Saturday");
         for (int r = 0; r < time.length; r++) { // top to bottom
            System.out.println(time[r] + "\t");
            for (int c = 0; c < sked[0].length; c++) { // left to right
               if (sked[r][c] == null) {
                  System.out.print("");
               } 
               else {
                  System.out.printf("%-2s", sked[r][c] + "\t\t");
               }
            // array elements accessed as table[row][col] ?
            }
         }
 
      }
   }

get this

Please input the Course,Day/s, and Time accordingly.

IT191,MTWHF,7:00

0

1

2

3

4

Please input the Course,Day/s, and Time accordingly.

IT191,MW,7:30

0

2

Please input the Course,Day/s, and Time accordingly.

IT195,T,8:00

1

Please input the Course,Day/s, and Time accordingly.

PEN193,S,8:00

5

Please input the Course,Day/s, and Time accordingly.



		Monday Tuesday Wednesday Thursday Friday Saturday

7:30	

IT191		IT195		IT191		IT191		IT191		PEN193		8:30	

												9:30	

												10:30	

												11:30	

												1:00	

												2:00	

												3:00	

												4:00

It was a bit neater than that output shown above but it still had the 7:30 up there in a weird spot and all the classes set to the same time period.