char* 转 string
const char *name = "hello";
String Str = name;
Serial.printf("%s\n", Str);
string 转 char*
String str = "hello";
char *p = (char *)str.c_str();
Serial.printf("%s\n", p);
char *转 char[]
const char *str = "hello";
char str1[10];
strncpy(str1, str, strlen(str) + 1); // 注意加1操作
Serial.printf("%s\n", str1);
char[] 转 char *
char str[] = "hello";
char *p = str;
Serial.printf("%s\n", p);
char[] 转 string
char st[] = "hel