Commit c7cef4d

#include <iostream>

int main() {

// 1. with Latin letters

int myVariable = 10;

// 2. case-sensitive

int MyVariable = 20;

int MYVARIABLE = 30; // MYVARIABLE != MyVariable

std::cout << "myVariable: " << myVariable << std::endl;

std::cout << "MyVariable: " << MyVariable << std::endl;

std::cout << "MYVARIABLE: " << MYVARIABLE << std::endl;

// 3. with underscores (`_`)

int my_variable = 40;

int _private = 50;

int __double_underscore = 60;

std::cout << "my_variable: " << my_variable << std::endl;

std::cout << "_private: " << _private << std::endl;

// 4. with digits (NEVER as start)

int var1 = 70;

int variable123 = 80;

int var_2_test = 90;

// int 1var = 100; // ❌ ERROR: cannot start with digit

std::cout << "var1: " << var1 << std::endl;

std::cout << "variable123: " << variable123 << std::endl;

// 5. arbitrarily long identifiers (every character is significant)

int thisIsAVeryLongIdentifierNameThatIsStillValidInCppAndEveryCharacterMatter = 110;

std::cout << "Long identifier 0: " << thisIsAVeryLongIdentifierNameThatIsStillValidInCppAndEveryCharacterMatter << std::endl;

// 6. MOST Unicode characters are ALLOWED (implementation-dependent)

// Common Unicode characters / USUALLY work:

// - Latin extended characters

// - Greek letters

// - Some mathematical symbols

// those / may NOT compile | ALL systems

// int café = 120; // Latin extended

// int α = 130; // Greek alpha

// int β = 140; // Greek beta

// Unicode / characters are NOT ALLOWED

// int 你好 = 150; // ❌ May not work

// int 😀 = 160; // ❌ Emojis are NOT allowed

// int ∑ = 170; // ❌ Many mathematical symbols are NOT allowed

// 7. EVERY character is significant

int temp = 300;

int temp_ = 310;

int _temp = 320;

int temp1 = 330;

int temp_1 = 340;

std::cout << "temp: " << temp << std::endl;

std::cout << "temp_: " << temp_ << std::endl;

std::cout << "_temp: " << _temp << std::endl;

std::cout << "temp1: " << temp1 << std::endl;

std::cout << "temp_1: " << temp_1 << std::endl;

return 0;

}