Thread: need help on an assignment :(

Here's some pseudocode for what you want, I believe. I'll leave the details and the translation to you...

DataStore()
1. continue := true
2. while continue
3.    do PrintMenu()
4.    selection := ReadSelection()
5.    if selection = 1 then AddStringAndIntegerPair()
6.    else if selection = 2 then PrintStringAndIntegerPairs()
7.    else if selection = 3 then PrintMultiplications()
8.    else continue = false
 
PrintStringAndIntegerPairs()
1. for i = 1 to len(store)
2.    do (string, integer) := store[i]
3.    print (string, integer)
 
PrintMultiplications()
1. for i = 1 to len(store)
2.    do (string, integer) := store[i]
3.    print (integer * i)

i always find it easiest to find out what problems i would need to
figure out b4 i actuly make it so ...

problems that would need to be solved

create an array that dosent have a set limit ( easy if u know how )
make the program run until u quit ( easy if u know how )
and read and validate numerical input from the user ( medium for newer programmers )

main runs method [top]
   top reads & validates input then runs 1 of the others [ add, printAll, multiply,quit ]
     add reads & validates the inputed info then stores it and returns to [top]
     printAll runs a loop to print all info then returns to [top]
     multiply reads & validate the input and gets the numbers to be multiplied then displays answer and returns to [top]
     quit is self explanitory XP

To learn the java syntax, I'd suggest Java nuts and bolts: Control Flow Statements to understand how to write for, while, and if/else statements to control the flow of your program.

A good idea would be to use helper methods. These are basic methods that will do small (or not small) tasks based on a list of parameters you pass to that method.

// declaring a simple helper method
 
public static void main(String[] args)
{
     printoutMenu(); // our helper method to print out a menu everytime it is called
}
 
public static void printoutMenu() // this line is the method signiture
{
     System.out.println("This is a simple menu");
     System.out.println("1. Hello world!");
     System.out.println("2. Hello moon!");
     System.out.println("3. Goodbye!");
}

To pass parameters to a method, simply add variable declarations to the method signature between the two parenthesis:

public static void printInt(int n) // an integer called n will be passed to this method. It will be treated like a local variable
{
     System.out.println("The integer was " + n);
}

To get a value back from a method, modify the method signature to have a return type (note: void means no return value).

public static [b]int[/b] getInt() // the stuff in bold is the return type
{
     return 3; // when this method gets called, this value will get returned
}
 
public static [b]double[/b] getDouble(boolean isRandom)
{
     if (isRandom)
     {
          return Math.random(); // a random double generated using Math.random
     }
     else
     {
          return 0.0;
     }
}

It is important to note that you can only return one thing from a method each time it is called, but each time that method is called the value returned doesn't necessarily have to be the same. You can also have multiple return statements in a method, so long as every control path ends with exactly one return value (note that methods with a void return type don't necessarily need to have a return statement at the end, it's understood that it will return nothing once the end of the method is reached).

@ hello
their is a work around for multiple non object returns
just use a string array if its mixed , or if its just numbers then a int array would work
all u have to do is add a loop to read the info from the array after it returns

[note] i try finding work arounds for everything i can XD

Regardless, you are only allowed to return one thing. But yes, what you return doesn't matter, so you could create an object to hold lot of different information and return that single object.

The other work-around is to use the pass by reference trick (only works with objects). This will allow you to modify any number of objects passed by reference to your method. However, there is one limit: you must operate on the object passed, you can't create a new object and try to change the reference to this new object (well, you could but if you do that new object will behave just like a local variable)

public void swap(int[] nums)
{
     // assume nums is an integer array of size 2
     int temp = nums[0];
     nums[0] = nums[1];
     nums[1] = temp;
}
 
public static void main(String[] args)
{
     int[] nums = {1,2};
     System.out.println("The current order: " + nums[0] + " " + nums[1]);
     swap(nums);
     System.out.println("The swapped order: " + nums[0] + " " + nums[1]);
}

[/work-around to the work-around]

Originally Posted by helloworld922

[/work-around to the work-around]

with a healthy side of pownage XD XP