int to char problem ?

#include<iostream>
#include<vector>
#include<string>
using namespace std;
class Stack
{
public :
Stack();
void push(char&);
void pop();
char getpop();
void output();

private:
vector<char_vector;
int topOfStack;
};
Stack::Stack():topOfStack(-1){}
void Stack::push(char &x)
{
topOfStack++;
_vector.push_back(x);
}
void Stack::pop()
{
topOfStack--;
}
char Stack::getpop()
{
return _vector[topOfStack--];
}
void Stack::output()
{
for(int i = topOfStack-1; i != -1 ; i--)
{
cout<<"item "<<i<<"= "<<_vector[i]<<endl;
}
}

int main()
{
string _str;
cin>>_str;
Stack _stack;
for(int i=0 ;i != _str.size(); i++)
{
if((_str[i] != '+') && (_str[i] != '*'))
{
_stack.push(_str[i]);
}
else if(_str[i] == '+')
{
int temp;
temp = _stack.getpop() + _stack.getpop();
char ctemp = (char)temp;
_stack.push(ctemp);
}
else if(_str[i] == '*')
{
int temp;
temp = _stack.getpop() * _stack.getpop();
char ctemp = (char)temp;
_stack.push(ctemp);
}
}
cout<<endl;
_stack.output();
return 0;
}

I have problem in line

else if(_str[i] == '+')
{
int temp;
temp = _stack.getpop() + _stack.getpop();
char ctemp = (char)temp;
_stack.push(ctemp);
}
else if(_str[i] == '*')
{
int temp;
temp = _stack.getpop() * _stack.getpop();
char ctemp = (char)temp;
_stack.push(ctemp);
}

b'coz ex. 56+
5 =53
6 =54
sum is 107 =k but i want 11 not k and push in vector is 11 plese
help.

re: int to char problem ?

bushido wrote:
Huh? Could you use sentences. Do you know the difference between
a character and it's numeric representation? Your "cast" doesn't
make this conversion, the numeric representation in char converts
with no modification to other integral times.

Since you're using single chars, how do you think a single push is
going to push two characters?

How are you going to distinguish 56 as two tokens 5 and 6 from
56? Me thinks you should introduce some punctuation into your
program and use a non-char integral type. for example:

5 6 +

could be parsed with

int operand;
if(cin >operand) {
// converted to int
_stack.push(operand);
} else {
cin.clear(); // clear error
string operator;
cin >operator;
switch(operator[0]) {
case '+':
...

re: int to char problem ?

>Note one fact that:

'0' -48
....
'5' -53
'6' -54

therefore:
'6' - '0' -6
'5' - '0' -5

You need to write "temp = (_stack.getpop() - '0') + (_stack.getpop() -
'0'); ".

re: int to char problem ?

bushido wrote:void push(const char&);
A better name would be 'top'.
Why is it 'int'?
Why do you need this?
Why do you need this? You can change the size of the vector.
You can simply do _vector.back();
Use _vector.size() instead of 'topOfStack'.
So, you push every character from the string into the stack until
you meet a plus or an asterisk.
When you add '5' and '6', what are you going to get? Write a simple
program:

#include <iostream>
int main() {
std::cout << "'5' + '6' is " << '5'+'6' << std::endl;
}

what do you get? Why?
Huh?
You probably need to convert the char you're about to insert into its
"meaning". '5' you need to convert to value 5. '6' to value 6. YOu
can do it by subtracting '0' from the char.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

re: int to char problem ?

temp = (_stack.getpop()-'0') + (_stack.getpop()-'0');

not work 56+ b'coz is ';'