Assigning one array element to another array.

[robgeek]

Hi, I was doing my assignment which states:
The user to enter a string which should be stored in Input_String[].
2) Then reverse the string and save it to another array called Output_String[].

I am having trouble with the second part where I need to save the string to another array. I am not sure how would I do. Here is what I have done:

// Hw-4_Bhasin.cpp : Defines the entry point for the console application.

//void rev_str();
#include "stdafx.h"
#include<iostream>
#include<string>
#include<cmath>
using namespace std;



int main()
{
	
	char option;
    void rev_str();
	double Mean(const int Data[5][4], int, int);
    void frequency(const int Data[5][4], int, int);

	cout<<"\n	Please choose from the given menu.";
	cout<<"\n	R{Reverse String]	M[Matrix]	Q[Quit]."<<endl;
	cin>> option;
	cin.ignore();

	switch(option)
	{
	case 'R':
	case 'r':
		 rev_str();
		 break;
    }
	system("pause");
	return 0;
}

void rev_str()
{
	const int MAX = 20;
	char Input_String[MAX];
	char Output_String[MAX];

 
	cout<<"Please enter a string."<<endl;
	cin.get(Input_String, MAX);

	for(int i=MAX; i>=0; i--)

    cout<<Input_String[i]<<endl;

	Output_String = Input_String; // ERROR: LEFT OPERAND MUST BE 1-VALUE.

	

		
	
	

	system("pause");
	return;
}

Thanks.

[Ancient Dragon]

you can not copy one character array to another using the = operator -- that only works with std::string.

The assignment wants you to copy the string in reverse order. The only way to do that is one character at a time, something like you did in the previous line when you displayed it in reverse order. When doing it one character at a time you can use the = assignment operator. Something like this, where s2 is the original string and s1 is the new string.

for(int i = 0; j = MAX-1; i < MAX; i++, j--)
   s1[j] = s2[i];

You can also do it with pointers

char* p1 = s1; // new string
char* p2 = s2 + strlen(s2); // original string
while( p2 > s2 )
   *p1++ = *p2--;

[chococrack]

//function prototypes
void rev_str();
double Mean(const int Data[5][4], int, int);
void frequency(const int Data[5][4], int,int);
// main
int main()
{
 . . .
return 0;
}
// functions
. . .

[robgeek]

Thanks. I made changes to my co[codde as you said but I am getting syntax errors which I am not able to solve lf anyone can take a look that would be really great.

// Hw-4_Bhasin.cpp : Defines the entry point for the console application.

//void rev_str();
#include "stdafx.h"
#include<iostream>
#include<string>
#include<cmath>
using namespace std;



int main()
{
	
	char option;
	char sub_menu;
	int Data[5][4] = {0, 0, 0, 0};
    void rev_str();
	double Mean(const int Data[5][4], int, int);
    void frequency(const int Data[5][4], int, int);

	cout<<"\n	Please choose from the given menu.";
	cout<<"\n	R{Reverse String]	M[Matrix]	Q[Quit]."<<endl;
	cin>> option;
	cin.ignore();

	switch(option)
	{
	case 'R':
	case 'r':
		 rev_str();
		 break;

	case 'M':
	case 'm':
		cout<<"Please choose from the following sub menu."<<endl;
		cout<<" A{Average]	F[Frequency]	M[Median]		P[Previous Menu]"<<endl;
		cin>> sub_menu;

		cout<<"Please enter 5 integer sets of 4 numbers."<<endl;
		cin>> Data[5][4];
     
	switch(sub_menu)
	{
	case 'A':
	case 'a':

		break;
	}





    }
	system("pause");
	return 0;
}

void rev_str()
{
	const int MAX = 20;
	char Input_String[MAX];
	char Output_String[MAX];

 
	cout<<"Please enter a string."<<endl;
	cin.get(Input_String, MAX);

		for(int i=0; int j= MAX-1;i<MAX; i++, j--)

    cout<<Input_String<<endl;

	Output_String[j] = Input_String[i];

	
	system("pause");
	return;
}

All errors point to for loop.

Errors:
Error 1 error C2146: syntax error : missing ')' before identifier 'i'
Error 3 error C2059: syntax error : ';'
Error 4 error C2059: syntax error : ')'
Error 5 error C2146: syntax error : missing ';' before identifier 'cout'
Error 6 error C2065: 'j' : undeclared identifier
Error 7 error C2065: 'i' : undeclared identifier

Thanks.

[Ancient Dragon]

>>for(int i=0; int j= MAX-1;i<MAX; i++, j--)

That's the wrong format. use a comma after int i = 0 , not a semicolon and don't use int j

Two more errors:
1) you need to use { and } for multi-line statements
2) You have i and j in reverse order.

for(int i=0, j= MAX-1;i<MAX; i++, j--)
    {
        cout<<Input_String<<endl;
        Output_String[i] = Input_String[j];
    }