Mastering Blockchain Programming with Solidity

The totalSupply variable stores the total token supply

The totalSupply state variable is defined in the contract as follows:

uint256 internal totalSupply_;

The totalSupply state variable is of uint256 type. This stores the sum of all of the tokens that exist. This variable gives you an idea of how many of these types of tokens have been generated in total and are held by EOA addresses.

You can also define the totalSupply state variable with the visibility of the variable set to public, as follows:

uint256 public totalSupply;

As we know, in Solidity, for the public state variables, the compiler auto-generates getter methods. In the same way, defining totalSupply as shown in the preceding code will auto-create a public totalSupply() view function, ...