java to c++

[spl]

Anyone who knows java and C++, can convert this java prog into c++.
This program is for sorting array of objects.

// objectSort.java
// demonstrates sorting objects (uses insertion sort)
// to run this program: C>java ObjectSortApp
////////////////////////////////////////////////////////////////
class Person
{
private String lastName;
private String firstName;
private int age;
//-----------------------------------------------------------
public Person(String last, String first, int a)
{ // constructor
lastName = last;
firstName = first;
age = a;
}
//-----------------------------------------------------------
public void displayPerson()
{
System.out.print(" Last name: " + lastName);
System.out.print(", First name: " + firstName);
System.out.println(", Age: " + age);
}
//-----------------------------------------------------------
public String getLast() // get last name
{ return lastName; }
} // end class Person
////////////////////////////////////////////////////////////////
class ArrayInOb
{
private Person[] a; // ref to array a
private int nElems; // number of data items
//--------------------------------------------------------------
public ArrayInOb(int max) // constructor
{
a = new Person[max]; // create the array
nElems = 0; // no items yet
}
//--------------------------------------------------------------
// put person into array
public void insert(String last, String first, int age)
{
a[nElems] = new Person(last, first, age);
nElems++; // increment size
}
//--------------------------------------------------------------
public void display() // displays array contents
{
for(int j=0; j<nElems; j++) // for each element,
a[j].displayPerson(); // display it
System.out.println("");
}
//--------------------------------------------------------------
public void insertionSort()
{
int in, out;

for(out=1; out<nElems; out++) // out is dividing line
{
Person temp = a[out]; // remove marked person
in = out; // start shifting at out

while(in>0 && // until smaller one found,
a[in-1].getLast().compareTo(temp.getLast())>0)
{
a[in] = a[in-1]; // shift item to the right
--in; // go left one position
}
a[in] = temp; // insert marked item
} // end for
} // end insertionSort()
//--------------------------------------------------------------
} // end class ArrayInOb
////////////////////////////////////////////////////////////////
class ObjectSortApp
{
public static void main(String[] args)
{
int maxSize = 100; // array size
ArrayInOb arr; // reference to array
arr = new ArrayInOb(maxSize); // create the array

arr.insert("Evans", "Patty", 24);
arr.insert("Smith", "Doc", 59);
arr.insert("Smith", "Lorraine", 37);
arr.insert("Smith", "Paul", 37);
arr.insert("Yee", "Tom", 43);
arr.insert("Hashimoto", "Sato", 21);
arr.insert("Stimson", "Henry", 29);
arr.insert("Velasquez", "Jose", 72);
arr.insert("Vang", "Minh", 22);
arr.insert("Creswell", "Lucinda", 18);

System.out.println("Before sorting:");
arr.display(); // display items

arr.insertionSort(); // insertion-sort them

System.out.println("After sorting:");
arr.display(); // display them again
} // end main()
} // end class ObjectSortApp
////////////////////////////////////////////////////////////////

 

[Hendrik Maryns]

spl schreef:

Anyone who knows java and C++, can convert this java prog into c++.

Yes. So?

H.
--
Hendrik Maryns
http://tcl.sfs.uni-tuebingen.de/~hendrik/
==================
http://aouw.org
Ask smart questions, get good answers:
http://www.catb.org/~esr/faqs/smart-questions.html


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[Ulrich Eckhardt]

Anyone who knows java and C++, can convert this java prog into c++.

I could, but I don't see a reason to do your homework. Mostly, it's just a
translation along these lines:
- String -> std::string.
- Person[] -> std::vector<Person>

Note that if you assume that a 'Person' object is copyable, i.e. that it is
a record with data for a person, you will not need to use 'new', which is
used differently in C++ than in Java. Lastly, you could save some effort
using std::sort, unless you are bound by the assignment to use insertion
sort.

Otherwise, I would suggest you start hacking and then, if problems come up
with the C++ code, post to a C++ newsgroup.

cheers

Uli

 

[spl]

yes, I know well about C++, but I just confused in this part,

int in, out;

for(out=1; out<nElems; out++) // out is dividing line
{
Person temp = a[out]; // remove marked person
in = out; // start shifting at out

while(in>0 && // until smaller one found,
a[in-1].getLast().compareTo(temp.getLast())>0)
{
a[in] = a[in-1]; // shift item to the right
--in; // go left one position
}
a[in] = temp; // insert marked item
} // end for

ie., assigning objects in C++, how will do this?

 

[spl]

ya..i have done it. Thanks mate!!

 

[Roedy Green]

Anyone who knows java and C++, can convert this java prog into c++.
This program is for sorting array of objects.

Are you asking someone to do this for you? Are you just commenting on
the similarity of Java and C++?

 

[Arne Vajhøj]

Anyone who knows java and C++, can convert this java prog into c++.

I could, but I don't see a reason to do your homework. Mostly, it's just a
translation along these lines:
- String -> std::string.
- Person[] -> std::vector<Person>

It is not obvious to me that a Java array should be converted
to a C++ collection (if you forgive me for using the Java term).

Arne

 

[Ulrich Eckhardt]

Anyone who knows java and C++, can convert this java prog into c++.

I could, but I don't see a reason to do your homework. Mostly, it's just
a translation along these lines:
- String -> std::string.
- Person[] -> std::vector<Person>

It is not obvious to me that a Java array should be converted
to a C++ collection (if you forgive me for using the Java term).

This is getting a bit OT here, but anyway....

I'm not a Java pro, rather a beginner myself, but IIUC Java arrays can hold
a variable number of elements, i.e. you can insert and delete elements,
right? That is why I suggested using std::vector as replacement in C++
(though std::list and std::deque will also work). Using arrays in C++ means
you have to specify the number of elements either at compile-time or when
invoking new. However, the latter has the distinct disadvantage that you
need to do manual resource management which std::vector doesn't suffer
from.

What would you have taken?

Uli

 

[Lew]

I'm not a Java pro, rather a beginner myself, but IIUC Java arrays can hold
a variable number of elements, i.e. you can insert and delete elements,
right? That is why I suggested using std::vector as replacement in C++
(though std::list and std::deque will also work). Using arrays in C++ means
you have to specify the number of elements either at compile-time or when
invoking new. However, the latter has the distinct disadvantage that you
need to do manual resource management which std::vector doesn't suffer
from.

from

 

[Arne Vajhøj]

spl wrote:
Anyone who knows java and C++, can convert this java prog into c++.
I could, but I don't see a reason to do your homework. Mostly, it's just
a translation along these lines:
- String -> std::string.
- Person[] -> std::vector<Person>

It is not obvious to me that a Java array should be converted
to a C++ collection (if you forgive me for using the Java term).

This is getting a bit OT here, but anyway....

I'm not a Java pro, rather a beginner myself, but IIUC Java arrays can hold
a variable number of elements, i.e. you can insert and delete elements,
right? That is why I suggested using std::vector as replacement in C++
(though std::list and std::deque will also work). Using arrays in C++ means
you have to specify the number of elements either at compile-time or when
invoking new. However, the latter has the distinct disadvantage that you
need to do manual resource management which std::vector doesn't suffer
from.

No - Java array are fixed size like in C/C++.

The equivalent of vector<Person> in Java would be

What would you have taken?

For a 1:1 translation: array.

Both C++ and Java probably should use a collection.

Arne