Mastering Blockchain Programming with Solidity

Using libraries with – using...for directive

We saw how to create a library in the previous section. Now, let's see how we can use those libraries in the contracts and make a call to the functions of the library.

To attach a library to the contract, we use a special directive called using X for Y;, where X is the library and Y is the data type. By defining this directive, we are saying that X is a library, we take all the functions from the X library, and allow those functions to be called on the Y data type. For example, the X library has a function called funcName(); in that case, you would be able to call Y.funcName() on the Y datatype. When funcName() is called, the first parameter to the funcName() function is passed as the Y datatype. ...