adding digits from a char array to an int

hi! im writing a console calculator that so far only supports addition. the user should be able to enter something like: 3 + 6
and get 9 returned
my troubles are that i dont understand how to seperate the numbers and store them in int variables so i can add them. i have 3 functions in this program.
findSign which locates the + sign
removeSpace which gets rid of all the spaces in the equation
add which actually adds all the numbers

heres my code :)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
#include<iostream>
#include<cstring>
using std::cout;
using std::cin;
using std::endl;
int findSign(char expression[], int length);
char* removeSpace(char* string, int length, char* spaceless, int& spaceCounter);
int add(char equation[], int loc, int length);

int main(void)
{
	//get equation from user
	const int max = 50;
	char entered[max];
	cin.getline(entered, 50, '\n');
	int len = strlen(entered);
	char* expression = new char[len];
	int length = sizeof expression/sizeof expression[0];
	
	//get rid of all spaces
	int spaceCounter = 0;
	char* equation = new char[length];
	equation = removeSpace(expression, length, equation, spaceCounter);

	//find the + sign and the total
	int loc = findSign(equation, length);
	int total = add(equation, loc, length); 

	cout << total;
	//clear memory and close the program
	delete[] expression;
	delete[] equation;
	expression = 0;
	equation = 0;
	cout << endl;
	return 0;
}

char* removeSpace(char* string, int length, char* spaceless, int& spaceCounter)
{
	//remove all the spaces by adding all characters that arent spaces to the spaceless array
	for (int i = 0; i < length; i++)
	{
		if (string[i] == ' ')
			continue;
		else
		{
			spaceless[spaceCounter] = string[i];
			spaceCounter++;
		}
	}
	return spaceless;
}

int findSign(char expression[], int length)
{
	//locate the + sign
	int location = 0;
	for (int i = 0; i < length; i++)
	{
		if (expression[i] == '+')
		{
			location = i;
		}
	}
	return location;
}

int add(char equation[], int loc, int length)
{
	//add the two numbers
	int num1 = 0, num2 = 0;
	int i = 0;
	for (; i < loc; i++)
	{
		num1 += (equation[i] - 48);					//subtract 48 to convert from ascii to a decimal
		cout << equation[i] << endl;
	}
	for (; i < length - 1; i++)
	{
		num2 += (equation[i] - 48);					//subtract 48 to convert from ascii to a decimal
		cout << equation[i] << endl;
	}
	return num1 + num2;
}
Last edited on
Topic archived. No new replies allowed.