Error: invalid operands of types ‘const char [35]’ and ‘const char [2]’ to binary ‘operator+’

Question

At the top of my file I have

#define AGE \"42\"

Later in the file I use ID multiple times including some lines that look like

Answer 1

AGE is defined as "42" so the line:

str += "Do you feel " + AGE + " years old?";

is converted to:

str += "Do you feel " + "42" + " years old?";

Which isn't valid since "Do you feel " and "42" are both const char[]. To solve this, you can make one a std::string, or just remove the +:

// 1.
str += std::string("Do you feel ") + AGE + " years old?";

// 2.
str += "Do you feel " AGE " years old?";