Ben Chuanlong Du's Blog

It is never too late to learn.

Rust Error "error: expected item, found 'let'"

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

The error message "error: expected item, found 'let'" is commonly encountered in Rust when you mistakenly place a let statement in an invalid location. A let statement can only be used …

Dealing With Environment Variables in Python

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. os.environ is a dict-like object containing environment variables as keys and their values as values. You can query the value of an environment variable using os.environ[ENV_VAR_NAME]. And you can set the value of an environemnt variable using os.environ[ENV_VAR_NAME] = val

Variables in Java

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. There are 3 different types of variables in Java: instance variables, local variables and argument variables. An instance variables will be initialized to default values if it is not initialized manually …