I keep getting undefined input error

Hello , im trying to make this gpa/cgpa calculator that asks the user for input , but whenever i reach the the input that requires a character it shows undifined error as shown in the screenshot :

Enter letter grade for course: A

Error using input

Undefined function or variable 'A'.

Error in Untitled11 (line 10)

Grade = input('Enter letter grade for course: ');

Answer 1

[Mathieu NOE]

hello

you want to request a string not a number , so the correct code is :

Grade = input('Enter letter grade for course: ',"s");

[rak crak]

Error using input

The second argument to INPUT must be 's'.

Error in Untitled11 (line 10)

grade = input('Enter letter grade for course: ',"s");

[Mathieu NOE]

ok

this can be due to which release you are working with (I have R2020b)

so look for the help of the function and correct if needed

[rak crak]

i use R2018a , will check help of the function , thank you.

[Cris LaPierre]

Try using single quotes for 's', similar to what you did for Course.

Grade = input('Enter letter grade for course: ','s');