How do I combine both string and array in a string variable in Arduino's C/C++ dialect? I tried to run below lines but doesnt work.
int j = 0;
String value1[] = {0,1,2,3};
String httpRequestData = "&value1=" + value1[i] + "";
//then number of j++
1 Answer
You need to initialize your string before concatenate different types.
More details here https://www.arduino.cc/en/Tutorial/StringAdditionOperator
int j = 0;
int value1[] = {0,1,2,3};
String httpRequestData = String("&value1=");
httpRequestData += value1[i];
7 Comments
bolov
"&value1=" + value1[i] doesn't do what you think it does and it is wrong.
Sir Jo Black
@bolov , I read the document of String in Arduino doc. I found that the String class has the capability to manage also integers. I've searched for String because I said that is not correct to use
sprintf(buff,"%d",value[i]) ... but now I cannot try if my concern is true! Elsewhere I think the correct way should be: sprintf(buff,"%d",value[i].toInt())
Ôrel
@bolov what this will do ? According to the Arduino doc this will concatenate. From the doc:
stringThree = stringOne + 123;bolov
@Ôrel
"&value1=" is a C string literal and value[i] is int. Maybe int value1[] is a typo in your answer.Ôrel
@bolov this is not a typo, as httpRequestData is a String, the magic of C++ will to the conversion and convert then concatenate the both as
String not a char * and an int, check the shared link. Not saying this is clean, but this is the arduino way to do |
doesnt workis not very clear.