c++ - Deprecated conversion from string literal to 'char*'

Question

I have a program which declares an array of strings like this:

char *colors[4] = {"red", "orange", "yellow", "blue"};

But I get the above compiler warning. It compiles but I'd rather use the non-deprecated way(if there is one). I've tried to find out what it means, but I can't seem to figure it out. I've heard using 'const' before 'char' works, but it would be helpful if someone could explain what the error means. Thanks.

Answer 1

The strings that you enter: "red", "organge" etc are "literal", because they are defined inside the program code itself (they are not read directly from disk, user input /stdin etc.).

This means that if at any point you try to write to your colors you will be directly accessing your original input and thus editing it. This would cause some undesired run-time errors.

Declaring it as a const will make sure that you will never try to write to this pointer and such a run-time error can be avoided.

const char *colors[4] = {"red", "orange", "yellow", "blue"};

If you ever feel like editing these values at runtime, then you should copy the strings first.