isalnum code example

Example 1: isalnum

isalpha() - To check Alphabets
isnumeric() - To check Number
isalnum() - To check both alphabates and number

Example 2: c++ isalphanum

string test = "Ab4 :";
std::isalnum(test[0]);	//true
std::isalnum(test[1]);	//true
std::isalnum(test[2]);	//true
std::isalnum(test[3]);	//false
std::isalnum(test[4]);	//false