George is creating a program that will ask the user to input their grade in school. George wants to prevent the program crashing if the user enters letter instead of number. Which of the following can be used
to prevent the program crashing?
1. Use a try-except block to catch any ValueError exceptions that may occur when attempting to convert the input to an integer.
Example code:
```python
try:
grade = int(input("Enter your grade: "))
except ValueError:
print("Invalid input. Please enter a number.")
```
2. Use the isnumeric() method to check if the input string consists only of numeric characters before attempting to convert it to an integer.
Example code:
```python
grade = input("Enter your grade: ")
if grade.isnumeric():
grade = int(grade)
else:
print("Invalid input. Please enter a number.")
```
Either of these methods can be used to handle the case where the user enters a non-numeric input and prevent the program from crashing.
George can use the following approach to prevent the program from crashing if the user enters a letter instead of a number:
1. Use a Try-Except block to catch any ValueError that occurs when trying to convert the user input to an integer.
2. Within the Try block, use the int() function to convert the user input to an integer.
3. If the conversion is successful, continue executing the program.
4. If a ValueError occurs, the program will jump to the Except block, where George can handle the error, for example by displaying an error message to the user and asking them to input the grade again.
Here's an example of how George can implement this in Python:
```python
try:
grade = int(input("Enter your grade: "))
# Continue executing the program with the grade variable
except ValueError:
print("Invalid input. Please enter a number for your grade.")
# Handle the error and ask the user to input the grade again
```
By using a Try-Except block, George can ensure that the program handles any potential errors caused by the user inputting a letter instead of a number, preventing the program from crashing.