Control Flow & Functions

C++ control flow (if, for, while) will look familiar if you've seen any C-family language. Functions must declare the type they return, and every parameter's type is fixed — the compiler checks all of it before your program ever runs.

• for (int i = 0; i < n; i++) { } is the standard counting loop.
• A function signature looks like double average(int total, int count).
• void return type means the function performs an action but returns nothing.
• Declaring a function before main() (or in a header file) lets you call it from anywhere.

💡 Practical Skill: Writing small, focused functions is just as valuable in C++ as in any language — and essential once programs grow past a single file.

#include <iostream>#include <string> std::string checkStatus(int classesAttended, int totalClasses) {    double rate = (double)classesAttended / totalClasses * 100;    if (rate >= 80) return "Eligible for certificate";    if (rate >= 60) return "Needs make-up session";    return "At risk — contact student";} int main() {    int attendance[] = {18, 15, 20, 9, 17};    int studentCount = 5;     for (int i = 0; i < studentCount; i++) {        std::cout << "Student " << (i + 1) << ": "                  << checkStatus(attendance[i], 20) << std::endl;    }    return 0;}