How to set minimum and maximum values for an integer?

Question

How do i add minimum and maximum values for an integer? I want an integer to never go down below zero like negative and never goes above 100

Here is the example:

int hp = 100;

std::cout << "You cast healing magic to yourself!" << std::endl;
hp += 20;
mp -= 25;

For example the health is 100 but when a healing magic is cast it became 120. The thing i want is i want it to stay as 100 no matter how many healing magic are cast upon.

Answer 1

You can use std::clamp:

hp = std::clamp(hp + 20, 0, 100);
mp = std::clamp(mp - 25, 0, 100);

Answer 2

You can use std::clamp as suggested by @TedLyngmo if you are using a compiler which supports C++ 17. If not, then you can write a simple function to manage the limits for hp and mp:

void change(int& orig, int val)
{
    int temp = orig + val;
    if (temp <= 0)
        temp = 0;
    else if (temp >= 100)
        temp = 100;
    orig = temp;
}

int main()
{
    int hp = 40, mp = 40;

    std::cout << "You cast healing magic to yourself!" << std::endl;
    
    change(hp, 50);
    change(mp, -25);

    std::cout << hp << " " << mp << std::endl;
}