I want to access a member variable of an object [closed] - c++

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When making a class how would I differentiate the two different class variables. I want to add elements in two vectors together and get a new vector with the sum of the two different numbers. In the code below when making an instance of a class I have access to it's vector but what about the one in parameters? number_blocks being the vector variable in the class BigInt
BigInt BigInt::add(const BigInt& number){
int flag = 0;
int carry = 0;
int sum = 0;
const int LIMIT = 9;
int size = number.length();
for(int i = 0; i < size; i++){
sum = number_blocks[i]// + number_blocks_number[i];
if(flag == 1){
sum = sum + carry;
flag = 0;
}
if(sum > LIMIT){
carry = sum / 10;
sum = sum % 10;
flag = 1;
}
number_blocks.push_back(sum);
}
return BigInt();
}

Answer 1

The same way you do number.length()
number.number_blocks[i]
BTW: you have to push the carry at the end (if nonzero).
Note: please ask specific questions. "I want to access a member variable of an object". show a one liner example. nobody cares about the rest.

Answer 2

Issues that I see with your implementation of BigInt::add:
You are returning an default instance of BigInt in the line:
return BigInt();
It makes sense to me that you would return a BigInt that is the result of adding two BigInts.
You are not taking into account the BigInts of varying length. For example, adding 187 with 85.
You are ignoring the last carry. If you add 9 and 9, you need to carry the 1.
The logic for computing the sum and the carry can be simplified to:
sum = this->number_blocks[i] + number.number_blocks[i] + carry;
carry = sum / 10;
sum = sum % 10;
You don't the variables flag and LIMIT.
Here's an implementation that addresses those issues.
BigInt BigInt::add(const BigInt& number){
int carry = 0;
int sum = 0;
// Compute the minimum number of digits from both the numbers.
size_t size1 = this->length();
size_t size2 = number.length();
size_t size = size1 < size2 ? size1 : size2;
BigInt ret;
// Process the digits that are in both the the first number and the
// second number.
for(size_t i = 0; i < size; i++)
{
sum = this->number_blocks[i] + number.number_blocks[i] + carry;
carry = sum / 10;
sum = sum % 10;
ret.number_blocks.push_back(sum);
}
// If the first number has more digits than the second, deal with the
// remaining digits from the first number.
if ( size1 > size )
{
for(size_t i = size; i < size1; i++)
{
sum = this->number_blocks[i] + carry;
carry = sum / 10;
sum = sum % 10;
ret.number_blocks.push_back(sum);
}
}
// If the second number has more digits than the first, deal with the
// remaining digits from the second number.
else if ( size2 > size )
{
for(size_t i = size; i < size2; i++)
{
sum = number.number_blocks[i] + carry;
carry = sum / 10;
sum = sum % 10;
ret.number_blocks.push_back(sum);
}
}
// Deal with the last carry.
if ( carry > 0 )
{
ret.number_blocks.push_back(carry);
}
return ret;
}