Do I need to malloc C-style strings? - arduino

Question

I recently started using Arduino so I still have to adapt and find the differences between C/C++ and the Arduino language.
So I have a question for you.
When I see someone using a C-style string in Arduino (char *str), they always initialize it like this (and never free it) :
char *str = "Hello World";
In pure C, I would have done something like this:
int my_strlen(char const *str)
{
int i = 0;
while (str[i]) {
i++;
}
return (i);
}
char *my_strcpy(char *dest, char const *src)
{
char *it = dest;
while (*src != 0) {
*it = *src;
it++;
src++;
}
return (dest);
}
char *my_strdup(char const *s)
{
char *result = NULL;
int length = my_strlen(s);
result = my_malloc(sizeof(char const) * (length + 1));
if (result == NULL) {
return (NULL);
}
my_strcpy(result, s);
return (result);
}
and then initialize it like this:
char *str = my_strdup("Hello World");
my_free(str);
So here is my question, on C-style Arduino strings, is malloc optional or these people just got it wrong?
Thank you for your answers.

Answer 1

In C++ it's better to use new[]/delete[] and not mix it with malloc/free.
In the Arduino there is also String class, that hides those allocations from you.
However using dynamic memory allocations in such restrained platform has its pitfalls, like heap fragmentation (mainly because String overloads + operator, so everyone is overusing it like: Serial.println(String{"something : "} + a + b + c + d + ......) and then wonders about mysterious crashes.
More about it on Majenko's blog: The Evils of Arduino String class (Majenko has highest reputation on the arduino stackexchange)
Basically with the String class your strdup code would be simple as this:
String str{"Hello World"};
String copyOfStr = str;