How to use strings in esp idf?

[Saskia]

I want to tuse the datatype STRING. But i can only do this when i include Arduino.h as a header (+ string.h).
Otherwise i get "'String' does not name a type". Is there another way without Arduino.h?

[kolban]

These days, I am a big fan of writing ESP32 Apps in C++ as opposed to C. I still use the ESP-IDF (not Arduino libraries).

When writing apps in C++, one has access to all the APIs exposed by newlib and ESP-IDF but in addition, a new treasure chest is opened up called the "C++ Standard Library". This is a rich set of libraries that are present with all conformant C++ implementations and the ESP32 is no exception.

Here is the WikiPedia article:

https://en.wikipedia.org/wiki/C%2B%2B_Standard_Library

and one facet of this is the class called:

std::string

see ... https://en.wikipedia.org/wiki/C%2B%2B_string_handling

and now we have the full power of super rich string handling that "just works".

[arnold.braun@gmx.de]

Hello,

where can i find the strings.

this don´t work at all:

#include <string.h> or #include "string.h"

class WifiClass {
protected:
public:
string ssid[2]= { "braun","" };

std::string Host = "ESP8266_me";

class WifiClass {
protected:
public:
string ssid[2]= { "braun","" };

std::string Host = "ESP8266_me";

[kolban]

Howdy,
The header you wish to include is

#include <string>

See also:

https://stackoverflow.com/questions/901 ... -extension

[arnold.braun@gmx.de]

Thanks

iit works

[Thanyasit]

Hello
this don´t work at all:
#include <stdio.h>
std::pwmSliderValue = "0";

I am unable to call these functions.
#include <string>
#include <iostream>

[davidzuhn]

You are compiling main.c, which is a C source file. You should rename this to main.cpp (and update your CMakeLists.txt or Makefiles accordingly) to have the tools recognize this as a C++ source file and compile it using the C++ compiler.

BTW, it's a lot easier to read the error messages if you cut and paste the text instead of posting a screenshot.