what() in c++ code example

Example 1: c++ what is %

x = 11 % 3;

Example 2: What is a ~ in c++

class Entity{
  public: 
  	~Destructor();
  	//This is a destructor, which destroys instances and can free up memory.
};

//Source for answer:
// https://stackoverflow.com/questions/1395506/in-c-what-does-a-tilde-before-a-function-name-signify

//Other Sources:
// https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_74/rzarg/cplr380.htm