cpp/cs104/copyassign/intarray

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Add a copy constructor to perform a deep copy of the array. Does that solve all your problems?
<p>
Also, go back to <tt>printVals(...)</tt>. <strong>Do you really need to pass-by-value?</strong> How could you avoid making a copy of the argument?

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Copied from problem cpp/cs104/copyassign/intarray_destructor (author: redekopp@usc.edu)
Copied from problem cpp/cs104/copyassign/intarray1 (author: redekopp@usc.edu)

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Choices
json list of string, bool pairs
e.g. [["good", true], ["bad", false]]

Correct answer
Template / Reference solution

Template / Reference solution

#include <iostream>
using namespace std;

class MyArray
{
public:
MyArray() { cout << "In default constructor" << endl;
dat = NULL; len = 0; }
MyArray(int d[], int num); //normal
\[
REDACTED
]\
~MyArray();
int& operator[](int loc) { return dat[loc]; }
int const & operator[](int loc) const { return dat[loc]; }
int size() const { return len; }
private:
int len; int *dat;

};

// Normal constructor
MyArray::MyArray(int d[], int num)
{
dat = new int[num]; len = num;
for(int i=0; i < len; i++){
dat[i] = d[i];
}
}

// Copy Constructor
\[ REDACTED ]\
{
cout << "In copy constructor" << endl;
\[
REDACTED
]\
}

MyArray::~MyArray()
{
cout << "In destructor" << endl;
delete [] dat;
}

\[
REDACTED
\show:
void printVals(MyArray arr)
]\

{
for(int i=0; i < arr.size(); i++){
cout << arr[i] << " ";
}
cout << endl;
}

int main()
{
int vals[] = {9,3,7,5};
MyArray a1(vals,4);
MyArray a2(a1); // calls copy constructor
MyArray a3 = a1; // calls copy constructor
MyArray a4;
a4 = a1; // calls default assignment

// how are the contents of a2, a3, a4
// related to a1
printVals(a1);
a1[0] = 11;
printVals(a2);
printVals(a4);

return 0;
}

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Property	Value
Description html markup shown to student	Add a copy constructor to perform a deep copy of the array. Does that solve all your problems? <p> Also, go back to <tt>printVals(...)</tt>. <strong>Do you really need to pass-by-value?</strong> How could you avoid making a copy of the argument?
Epilogue html markup shown when solved	remove
Public permissions	remove
Remarks Comments, history, license, etc.	Copied from problem cpp/cs104/copyassign/intarray_destructor (author: redekopp@usc.edu) Copied from problem cpp/cs104/copyassign/intarray1 (author: redekopp@usc.edu) remove
Engine
Choices json list of string, bool pairs e.g. `[["good", true], ["bad", false]]`
Correct answer
Template / Reference solution
Template / Reference solution	#include <iostream> using namespace std; class MyArray { public: MyArray() { cout << "In default constructor" << endl; dat = NULL; len = 0; } MyArray(int d[], int num); //normal \[ REDACTED ]\ ~MyArray(); int& operator[](int loc) { return dat[loc]; } int const & operator[](int loc) const { return dat[loc]; } int size() const { return len; } private: int len; int *dat; }; // Normal constructor MyArray::MyArray(int d[], int num) { dat = new int[num]; len = num; for(int i=0; i < len; i++){ dat[i] = d[i]; } } // Copy Constructor \[ REDACTED ]\ { cout << "In copy constructor" << endl; \[ REDACTED ]\ } MyArray::~MyArray() { cout << "In destructor" << endl; delete [] dat; } \[ REDACTED \show: void printVals(MyArray arr) ]\ { for(int i=0; i < arr.size(); i++){ cout << arr[i] << " "; } cout << endl; } int main() { int vals[] = {9,3,7,5}; MyArray a1(vals,4); MyArray a2(a1); // calls copy constructor MyArray a3 = a1; // calls copy constructor MyArray a4; a4 = a1; // calls default assignment // how are the contents of a2, a3, a4 // related to a1 printVals(a1); a1[0] = 11; printVals(a2); printVals(a4); return 0; }
Java test suite See manual
C++ test suite json list of stdin/args tests e.g. `[{"stdin":"hi", "args":["4", "5"]}, {"stdin":"noargs"}]` to just run once with no input use `[{}]`	[{}]
C++ test suite See manual
Forbidden substrings json list of strings e.g. `["for","while"]`	remove
Solution visibility	remove
Java imports json list of importables e.g. `["java.util.*"]`	remove
Override Java classname else defaults to websheet name	remove
Dependent on other websheets? json list of websheet names in this folder e.g. `["DataStructure"]`	remove
Is example? i.e., just a demo	remove
Add compiler flag(s) json list of flags e.g. `["-Wno-unused-variable"]`	["-Wno-unused-variable"] remove
Remove default compiler flag(s) json list of flags see default_cppflags e.g. `["-Wno-write-strings"]`	remove

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