Operators

Arithmetic operators are +, -, *, /, and %. Integer division discards the fractional part; remainder works on integers. Relational operators compare values, logical operators combine conditions, and assignment operators update objects.

int total{17};
int groups{5};
int each = total / groups;      // 3
int left = total % groups;      // 2
bool valid = groups > 0 && each >= 0;
total += 3;

&& and || short-circuit, so the right operand may not run. This makes pointer != nullptr && pointer->ready() safe. Do not confuse logical operators with bitwise &, |, ^, ~, <<, and >>.

Bits and flags

#include <cstdint>

constexpr std::uint8_t read{1u << 0};
constexpr std::uint8_t write{1u << 1};
std::uint8_t permissions{read | write};
bool canWrite = (permissions & write) != 0;

Use unsigned types for deliberate bit manipulation. Shifts by an invalid count and signed overflow can produce undefined behavior.

Precedence is not documentation

Multiplication binds more tightly than addition, and assignment binds weakly, but parentheses communicate grouping better than memorized tables. Prefix ++i increments then yields the new value; postfix i++ yields the old value and may require a temporary. C++20’s <=> can synthesize consistent ordering operations for value types. Avoid expressions that modify and inspect the same value in confusing ways; split work into named steps.