Unexpected output from function

[1Ck93TCk]

Hello,
I have this simple math program with multiple functions. The purpose of the program is just so I can better understand how functions work.

If I isolate one if statement and its corresponding function, it works fine. But if I add another function, everything becomes unexpected and the subtraction function performs addition, etc.

Please help me out. I've been looking at this program for hours and I can't figure out why it's acting this way.

Thank you!

 #include <iostream>

using namespace std;

void addition(int first, int second, int &result, char symbol);
void subtraction(int first, int second, int &result, char symbol);
void multiply(int first, int second, int &result, char symbol);
void divide(int first, int second, int &result, char symbol);
void modulo(int first, int second, int &result, char symbol);

int main()
{
    int first = 0;
    int second = 0;
    int result = 0;
    char symbol;


    cout << "Enter an integer: ";
    cin >> first;
    cout << "Enter another integer: ";
    cin >> second;
    cout << "Select an operator(+, -, * , /, %): ";
    cin >> symbol;

    if(symbol = '+')
       addition(first, second, result, symbol);

    if(symbol = '-')
        subtraction(first, second, result, symbol);

    if(symbol = '*')
        multiply(first, second, result, symbol);

    if(symbol = '/')
        divide(first, second, result, symbol);

    if(symbol = '%')
        modulo(first, second, result, symbol);


    cout << "The result is " << result << "." << endl;
}

void addition(int first, int second, int &result, char symbol)
{
    result = first + second;
}

void subtraction(int first, int second, int &result, char symbol)
{
    result = first - second;
}

void multiply(int first, int second, int &result, char symbol)
{
    result = first * second;
}

void divide(int first, int second, int &result, char symbol)
{
    result = first / second;
}

void modulo(int first, int second, int &result, char symbol)
{
    result = first % second;
}

[deleted account xyzzy]

if(symbol = '+') should be if(symbol == '+'). Checking for equality is ==.

You are assigning a value to symbol, which is always treated as being true.

You need to change all of the checks in your if statements.

[1Ck93TCk]

And it works! Thank your for the quick response!