CODEWITHSUNDEEP
c++arraysstringarduino
user6064424
user6064424

Reputation:

Append String object to character array in Arduino

I am using Arduino. I would like to append a String object to an array of characters.

String msg = "ddeeff"

char charArr[1600];

//assume charArr already contains some string
//How can I do something like this to append String to charArray?
charArr = charArr + msg;

Upvotes: 5

Views: 10386

Answers (2)

guagay_wk
guagay_wk

Reputation: 28030

This will work for Arduino String object. 

strcat( charArr, msg.c_str() );

String object msg gets converted into an array of characters with the String method c_str(). Then, you can use strcat() to append the 2 arrays of characters.

As mentioned by Rakete1111, it is undefined behavior if charArr is not big enough

Upvotes: 4

Rakete1111
Rakete1111

Reputation: 48938

String has a operator+ which takes a const char*, and it also has a c_str() function, which converts it to a const char*.

You can combine them to get the desired result:

String temp = charrArr + msg; //Store result in a String

//Copy every character
std::strncpy(charArr, temp.c_str(), sizeof(charrArr));

Upvotes: 1

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