在寫 C 語言時

char *week[] = {
  "Friday",
  "Saturday",
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday"
};

是沒問題的，

但是在寫 C++ 時，

char *week[] = {
  "Friday",
  "Saturday",
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday"
};

卻會跑出警告：

test.cpp:2:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    2 |   "Friday",
      |   ^~~~~~~~
test.cpp:3:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    3 |   "Saturday",
      |   ^~~~~~~~~~
test.cpp:4:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    4 |   "Sunday",
      |   ^~~~~~~~
test.cpp:5:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    5 |   "Monday",
      |   ^~~~~~~~
test.cpp:6:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    6 |   "Tuesday",
      |   ^~~~~~~~~
test.cpp:7:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    7 |   "Wednesday",
      |   ^~~~~~~~~~~
test.cpp:8:3: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
    8 |   "Thursday"
      |   ^~~~~~~~~~

解決方法：加上 const 就可以了

const char *week[] = {
  "Friday",
  "Saturday",
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday"
};

參考資料：
https://blog.csdn.net/whatday/article/details/106267398