1. switch case multi-branch structure
2. try catch to solve the exception
3. For loop It is
generally more convenient to use for loop to know the number of loops
The nine-nine multiplication table using the for loop:
square
triangle
4. The while loop judges first, and then executes the loop. Example: 80,000 trainees were trained in 2006, an annual increase of 25%. According to this growth rate, in which year the number of trainees will be When reaching 200,000 people,
break is used in the loop to exit the current loop.
5. The do while loop executes the loop body once and then judges whether the condition is established
