a value of type "const char *" cannot be assigned to an entity of type "char" C OOP

I am creating a class to calculate a grade for a user in C++ and I am coming across a simple yet annoying problem. I know what the errors means but I don't understand how to fix it and changing to a string actually fixes the issue but this is not what I want to do.

here is the error: const char *" cannot be assigned to an entity of type "char

Code

 #include <string> using namespace std; class Gradecalc { public: Gradecalc() { mark = 0; } int getmark() { return mark; } void setmark(int inmark) { mark = inmark; } void calcgrade() { if (mark >=70) { grade = "A"; //**ERROR IS HERE** } } char getgrade() { return grade; } private: int mark; char grade; //VARIABLE IS DECLARED HERE }; 

4 Answers

C++ has two types of constants consisting of characters - string literals and character literals.

• String literals are enclosed in double quotes, and have type of const char *
• Character literals are enclosed in single quotes, and have type char.

String literals allow multiple characters; character literals allow only one character. The two types of literals are not compatible: you need to supply a variable or a constant of a compatible type for the left side of the assignment. Since you declared grade as a char, you need to change the code to use a character literal, like this:

grade ='A'; 

C and C++ use double quotes to indicate "string literal", which is very different from a "character literal".

char (which is signed) is a type capable of storing a character representation in the compiler's default character set. On a modern, Western PC, that means ASCII, which is a character set that requires 7-bits, plus one for sign. So, char is generally an 8-bit value or byte.

A character literal is formed using single quotes, so 'A' evaluates to ASCII code 65. ('A' == 65).

On the other hand, "A" causes the compiler to write char(65) + char(0) into a part of the output program and then evaluates the expression "A" to the address of that sequence; thus it evaluates to a pointer to a char sequence, but they're in the program data itself so they are not modifiable, hence const char*.

You want

grade = 'A'; 

Replace

grade = "A"; 

by

grade = 'A'; 

You can only assign char to char, you cannot assign string to single char, and that is what you are trying to do.

Grade is a char variable, "A" is a const char* type.

You cannot assign const char* into char varible.

double quote means const char*, and single qoute means char.

to fix that, replace:

grade="A"

with

grade='A'.