Conditionals

if runs what's inside it when its condition is true, else if adds another condition that's checked when none of the ones before it were true, and else takes everything left over. The condition goes between parentheses and the code to run goes between curly braces. The branches are checked in order and only the first one whose condition is true runs, so start with the invalid case and then work down from the highest cutoff. You combine conditions with && (and), || (or) and ! (not), as in if (hp < 0 || hp > maxHp).

There are two mistakes C++ accepts without a single complaint. The first is writing = instead of ==: if (hp = 0) doesn't compare anything, it sets the health to zero, so the condition is never true. The second is writing a comparison the way you would in math: if (50 <= score <= 74) works out 50 <= score first, which gives 0 or 1, and both are less than 74, so the condition is always true. The correct way is to write it as two conditions: score >= 50 && score <= 74.

switch compares a single value, a whole number or a character, against a list of fixed values: each value gets a case, and default handles anything that didn't match. Execution starts at the matching case and keeps going through the ones below it until it reaches a break or a return, so if you forget them, the next case runs too. That same behavior is what lets you stack two cases on top of one piece of code, like case 'w': case 'W':. And switch doesn't work with std::string.