1, user-defined variables
1.1 What is a variable
2.2 Variable setting rules
2.3 Classification of variables
2.4 Local variables (user-defined variables)
2, Environment Variables
2.1 What is the environment variable
2.2 Set Environment Variables
3.3 System environment variables common
Case:
3, the position of the variable parameter
3.1 Location parameter variables
Case 1: Addition Calculator
The difference between $ *, $ @ $ # of: Case 2
Case 3: $ * and $ @ the difference
4, predefined variables
4.1 predefined variables
The difference between $$ and $: Case 1!
4.2 accept keyboard input
Case:
