C++ 04/25

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

const int BMI_CONST=703;

// modern c++ compilers are mostly read-forward
//function prototype - I promise I'll define my function later!
double calcBmi(double j=0, double k=0); //- can't specify default args twice!
// double calcBmi(double j, double k);
// double calcBmi(double,double);
//more than one fx prototype will work unforuntaely

//we ONLY have to do function prototypes when the function proceeds main instead of preceeding it!

void foo() {
    cout << "I'm before!";
}

int main(){ //command line arguments
    foo();
    // BMI_CONST = BMI_CONST + 1; => ++ // no can do with a constant!

    int i;
    cout << i; //0 because i has not been defined yet!
    i = 9;

    cout<< "Hello World" << std::endl;
    cout<< "Our C++ version is:" << __cplusplus << "\n" << endl; // we covered how this varies with stdC++ flag

    cout << "Enter weight and height" << endl;
    double height, weight;
    cin >> height >> weight;

    // type identifier = expression
    // any operation to the right of the assignment operator (==) is considered an expression!

    //TODO: discuss literal default values
    // "matt" -> char* arr

    double blah = 1 + 2 ; //this is an expression!
    double bmi = calcBmi(height, weight); //make a copy of the data of our local variables and pass that into the function!
    //position based arguments.

    if (int bmi2 = calcBmi(height, weight); bmi2 < 2000) {
        cout << "You're skinny!";
    } else cout << "You're overweight!";

    cout << "Your BMI is: " << bmi << endl;
    cout << "Type cast " << (int) (bmi) << endl;

    unsigned char uc = 149;
    signed char sc = (signed char) (uc);
    //truncation is the act of reducing bits which results in a loss of precision
    // 8bits unsigned => 8bits
    cout << (int) (sc); //numerical overflow! go from 8 bit signed char to 32 bit integer

    //TODO
    switch((int) (calcBmi(height,weight))){

    }



    //TODO: default vals!
    //default arguments allow for magic!
    cout << "Default args magic!: " << calcBmi() << endl;

    return 0;
}
//this is called copy by value!
double calcBmi(double h, double w) { //doesn't matter if I name the params the same as the name of the variables passed in
    // h = 93209; // the value in main() does NOT change!
    return (BMI_CONST*w)/ (h);
}

//Formula: 703 x weight (lbs) / [height (in)]2