How to use the atoi() function?

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1

Hi..
How do I use the atoi() function to convert a String such as my_string = "123" to an integer?
I tried atoi(my_string) but I get the following error

"cannot convert String to const char for argument '1' to int atoi(const *char)...

2

Post your whole code?

But just a tip - atoi works with char* strings, not the String class.

3

You need to convert your String object to a Character Array.

4

Thanks James.. that's what I needed.
Could you show my a code example? The documentation page doesn't have any.. I'm confused about what it means by "the supplied buffer".

5 
  char buf[my_string.length()+1];
  my_string.toCharArray(buf, my_string.length()+1);

Need to add one since the string is null terminated.

2 Likes
6

Thanks a lot..

7

With the curent IDEs you should be able to use the below:

int value = my_string.toInt();