README.md

SimpleMap

Associative arrays with Arduino!

Nothing big, just my own implementation of an associative array - also known as Map or HashMap (when you're coming from Java) for all kind of Arduino projects.

I wrote it to use in my Arduino projects and to learn more about datastructures and C++.

Installation

1. Download the source code from GitHub.
2. Unzip and rename the Folder name to "SimpleMap".
3. Paste it in your Library folder (Usually located somewhere at documents/Arduino/libraries).
4. Restart the Arduino IDE.

You can also just download the SimpleMap.h file and paste it in your Arduino sketch folder.

Usage

Include the library

#include <SimpleMap.h>  

Creating a map

// A map of strings
// Please not that it's necessary to provide a compare function, because it's needed to keep the map sorted!  
SimpleMap<String, String> *myMap = new SimpleMap<String, String>([](String &a, String &b) -> int {
	if (a == b) return 0;      // a and b are equal
	else if (a > b) return 1;  // a is bigger than b
	else return -1;            // a is smaller than b
});

Getting the map size

int theSize = myMap->size();

Adding elements

myMap->put("one", "1");
myMap->put("two", "2");
myMap->put("three", "3");

Getting elements

// get value of element with key "one"
String one = myMap->get("one");

// get index of element with key "one"
int i = myMap->getIndex("one");

// get key of element at index i
String oneKey = myMap->getKey(i);

// get value of element at index i
String oneValue = myMap->getData(i);

// check if element is in list
bool hasOne = myMap->has("one");

Replacing elements

// to replace or change a value is the same operation as to add value
myMap->put("one", "1"); // adds element with key "one" and value "1"
myMap->put("one", "11"); // sets the value of element with key "one" to "11"

Removing elements

// remove element with key "one"
myMap->remove("one");

// remove element at index 0
myMap->remove(0);

// clear() will erase the entire map, leaving it with 0 elements
myMap->clear();

// Please note that clear() wont free memory from pointers, you have to manually delete/free those!
// Example:
while(myMap->size() > 0){
	delete myMap->get(0).somePointer;
	myMap->remove(0);
}

Locking the map

// disables to remove() and put() fore new elements (changing values is allowed!)
myMap->lock();

// Please note that clear() will unlock the map again! A locked map does not protect against clear()

// allow put() and remove() again
myMap->unlock();

// ask if map is locked
bool isLocked = myMap->isLocked();