Shell course summary

Functions and arrays
1. Write a function to print green OK and red FAILED, and judge whether there are parameters. If there is a parameter, it is Ok, and if it does not exist, it is FAILED;
2. Write a function, to determine whether there is no position parameter, if there is no parameter, an error will be prompted;
3. Write a function to implement two numbers as parameters and return the maximum value;
4. Write a function to implement two integer bit parameters, calculateAddition, subtraction, multiplication and division.

Task 1:

Task two:

Task three:

Task four: