If Statement containing math

[Avi24]

Can an if statement contain a math function?


For example:

cout << endl << "Utilities: " << "$ "<< user.utilities << endl;
	if (x > y)
	{
		cout << "Your x was over the budget\n";
	}
	else
	{
		cout << "Your x was under the budget\n";
	}

Can I go into the if statement and modify it so that the cout also provides a numerical value? Can I somehow show in an equation from the if statement how much x exceeds y? (or vice-versa)

[Dy7SLyTq]

i guess so, but i think you are more looking for the terenary operator. it is used as:
(condition) ? (if condition is true) : (if condition is false);

so how you would use it here:

cout << endl << "Utilities: " << "$ "<< user.utilities << endl << (x > y) ? "Your x was over the budget\n" : "Your x was under the budget\n";

[Avi24]

Can then the terenary operator have a function in it? I want the equation to show how much x exceeds y, (or how much x is less than y). In other words, I would like the operator to show the results, not just give the word report.

[Dy7SLyTq]

yeah sure

[Avi24]

I would need to define the equation beforehand? Or can I just literally put it in the operator? I tried putting in

by value (total.housing)

where:

total.housing = user.housing - fixed.housing; Defined in a prior void equation, but got the error "Member Reference Type base "double", is not a structure or a union."

[Dy7SLyTq]

your not being very clear in your posts. could you please post your code?

[xismn]

Any function can be implicitly translated to an expression.
Any expression can be implicitly translated to a boolean value.
Conditional control structures make use of boolean values.

[Avi24]

Here is the code:

#include <iostream>
using namespace std;

struct MonthlyBudget
{
	double housing,
    utilities,
    householdExpenses,
    transportation,
    food,
    medical,
    insurance,
    entertainment,
    clothing,
    miscellaneous;
    
	MonthlyBudget(double h= 0, double u= 0, double he = 0, double t= 0, double f= 0, double m= 0, double i= 0, double e= 0, double c= 0, double misc= 0)
	{
		housing = h;
		utilities = u;
		householdExpenses = he;
		transportation = t;
		food = f;
		medical = m;
		insurance = i;
		entertainment = e;
		clothing = c;
		miscellaneous = misc;
	}
    
};

void equations()
{
    double total;
    double user;
    double fixed;
    
    total.housing = user.housing - fixed.housing;
}


void getAmount(MonthlyBudget &);
void displayAmount(MonthlyBudget &, MonthlyBudget &);

int main()
{
	MonthlyBudget fixed(500.00, 150.00, 65.00, 50.00, 250.00, 30.00, 100.00, 150.00, 75.00, 50.00);
	MonthlyBudget user;
    
	getAmount(user);
	displayAmount(user, fixed);
    
	return 0;
}

void getAmount(MonthlyBudget &user)
{
	cout << endl << "Please enter your monthly expenses:\n";
	cout  << endl << "Housing: ";
	cin >> user.housing;
	cout << endl << "Utilities: ";
	cin >> user.utilities;
	cout << endl << "Household Expenses: ";
	cin >> user.householdExpenses;
	cout << endl << "Transportation: ";
	cin >> user.transportation;
	cout << endl << "Food: ";
	cin >> user.food;
	cout << endl << "Medical: ";
	cin >> user.medical;
	cout << endl << "Insurance: ";
	cin >> user.insurance;
	cout << endl << "Entertainment: ";
	cin >> user.entertainment;
	cout << endl << "Clothing: ";
	cin >> user.clothing;
	cout << endl << "Miscellaneous: ";
	cin >> user.miscellaneous;
}

void displayAmount(MonthlyBudget &user, MonthlyBudget &fixed)
{
	cout << endl << "Here are your individual totals for the month:\n";
	cout << endl <<  "Housing: " << "$ " << user.housing << endl;
	if (user.housing > fixed.housing)
	{
		cout << "Your housing expenses was over the budget, by value (total.housing)\n";
	}
	else
	{
		cout << "Your housing expenses was under the budget\n";
	}
    
	cout << endl << "Utilities: " << "$ "<< user.utilities << endl;
	if (user.utilities > fixed.utilities)
	{
		cout << "Your utilities expenses was over the budget\n";
	}
	else
	{
		cout << "Your utilities expenses was under the budget\n";
	}
    
	cout << endl << "Household Expenses: " << "$ " << user.householdExpenses << endl;
	if (user.householdExpenses > fixed.householdExpenses)
	{
		cout << "Your household expenses was over the budget\n";
	}
	else
	{
		cout << "Your household expenses was under the budget\n";
	}
    
	cout << endl << "Transportation: " << "$ " << user.transportation << endl;
	if (user.transportation > fixed.transportation)
	{
		cout << "Your transportation expenses was over the budget\n";
	}
	else
	{
		cout << "Your transportation expenses was under the budget\n";
	}
    
	cout << endl << "Food: " << "$ " << user.food << endl;
	if (user.food > fixed.food)
	{
		cout << "Your food expenses was over the budget\n";
	}
	else
	{
		cout << "Your food expenses was under the budget\n";
	}
    
	cout << endl << "Medical:: " << "$ " << user.medical << endl;
	if(user.medical > fixed.medical)
	{
		cout << "Your medical expenses was over the budget\n";
	}
	else
	{
		cout << "Your medical expenses was under the budget\n";
	}
    
	cout << endl << "Insurance: " << "$ " << user.insurance << endl;
	if (user.insurance > fixed.insurance)
	{
		cout << "Your insurance expenses was over the budget\n";
	}
	else
	{
		cout << "Your insurance expenses was under the budget\n";
	}
    
	cout << endl << "Entertainment: " << "$ " << user.entertainment << endl;
	if (user.entertainment > fixed.entertainment)
	{
		cout << "Your entertainment expenses was over the budget\n";
	}
	else
	{
		cout << "Your entertainment expenses was under the budget\n";
	}
    
	cout << endl << "Clothing: " << "$ " << user.clothing << endl;
	if (user.clothing > fixed.clothing)
	{
		cout << "Your clothing expenses was over the budget\n";
	}
	else
	{
		cout << "Your clothing expenses was under the budget\n";
	}
    
	cout << endl << "Miscellaneous: " << "$ " << user.miscellaneous << endl;
	if (user.miscellaneous > fixed.miscellaneous)
	{
		cout << "Your miscellaneous expensees was over the budget\n";
	}
	else
	{
		cout << "Your miscellaneous expenses was under the budget\n";
	}
    
	double userBudget = user.housing + user.utilities + user.householdExpenses + user.transportation + user.food + user.medical + user.insurance + user.entertainment + user.clothing + user.miscellaneous;
	double fixedBudget = fixed.housing + fixed.utilities + fixed.householdExpenses + fixed.transportation + fixed.food + fixed.medical + fixed.insurance + fixed.entertainment + fixed.clothing + fixed.miscellaneous;
    
	cout << endl << "Total expenses for the month: $ " << userBudget;
    
	if(userBudget > fixedBudget)
	{
		cout << endl << "Your expenses exceed your monthly average budget\n";
	}
	else
	{
		cout << endl << "Your expenses are under your monthly average budget\n";
	}
}

I want the if/else statements to show values, not just give a yes or no answer.

[xismn]

I would use a loop.

#include <iostream>
#include <iomanip>
#include <cmath>

int main(int argc, char* argv[]) {

	const short NUM_ITEMS = 10;

	const char* items[NUM_ITEMS]	= {"housing", "utilities", "household", "transportation", "food", "medical", "insurace", "entertainment", "clothing", "miscellaneous"};
	const double fixed[NUM_ITEMS]	= {500.00, 150.00, 65.00, 50.00, 250.00, 30.00, 100.0, 150.00, 75.00, 50.00};
	double expenses[NUM_ITEMS]	= {100.00, 200.00, 100.00, 200.00, 100.00, 200.00, 100.00, 200.00, 100.00, 200.00};//possible expenses

	for(unsigned short i=0; i<NUM_ITEMS; ++i) {
		std::cout << "Your " << items[i] << " expenses were " << (expenses[i]>fixed[i]?"over":"under") << " the budget by $" << std::fixed << std::setprecision(2) << abs(fixed[i]-expenses[i]) << std::endl;
	}

	std::cin.get();
	return 0;
}

I've elected to make matching fixed costs and expenses qualify as "under" the budget.

[Avi24]

I think I am going to bang my head repeatedly. I figured out what I was supposed to do:

Instead of this:
cout << "Your housing expenses was over the budget\n";

I did this:
cout << "Your housing expenses was over the budget, by value: " <<user.housing - fixed.housing <<"\n";

And I found the specifications I needed.