How to convert String to char*

Using Arduino Programming Questions
1

Hello.
My code is:

uint8_t buf[VW_MAX_MESSAGE_LEN];
uint8_t buflen=VW_MAX_MESSAGE_LEN;
if (vw_get_message(buf, &buflen))
{
int i;
for (o = 0; o < buflen; o++)
{
}

if (o == buflen) {

hashMes = hashMes + String(buf[o]);

hashMes.toCharArray(hashMes, o);

but i keep getting an error message: "no known conversion for argument 1 from 'String' to 'char*'
no matching function for call to 'String::toCharArray(String&, int&)'
"
Thanks for help.

PS: I'm still a starter so don't be angre with me if this post is stupid. :smiley:

2

Post you whole code within code tags. Don't know how? Read the How to use this forum post.

3

Stop using Strings in the first place. Then you won't need to convert a String to a string.

4

Sending a String instance the message '.c_str()' will retrieve a pointer to its immutable backing c style string.

5

lloyddean:
Sending a String instance the message '.c_str()' will retrieve a pointer to its immutable backing c style string.

Sounds like Objective C-speak.

6

Or Swift, or ....

In a non-c++ zone at the moment!

7

PaulS:
Stop using Strings in the first place. Then you won't need to convert a String to a string.

How should i do it instead?

8

I'm getting next to nothing from your code fragments.

Perhaps more code and a description of what you're doing would entice others to provide more useful suggestions?

9

I'm getting an message from an radio module and want to hash the message. You'll get the full code if i'm back at the pc.