p5.js NumberDict maxKey() Method

The maxKey() method of p5.NumberDict in p5.js is used to find the highest key value in a number dictionary. A key-value pair is a set of two values that are mapped to each other. These values can be accessed by querying this dictionary using the key portion of the pair. A number dictionary can store multiple key-value pairs that can be accessed using the methods of the dictionary.

Syntax:

maxKey()

Parameters: This function does not accept any parameters.

Return Value: It returns a Number value that is the highest key in the number dictionary.

The example below illustrates the maxKey() method in p5.js:

Example 1:

Javascript

function setup() {
  createCanvas(500, 300);
  textSize(16);

  text("Click on the button to add new " +
       "values or get the highest key",
       20, 20);

  text("Key:", 20, 60);
  text("Value:", 160, 60);

  key_input = createInput('1');
  key_input.position(70, 50);
  key_input.size(40);

  val_input = createInput('1');
  val_input.position(220, 50);
  val_input.size(40);

  setBtn = createButton("Add new item");
  setBtn.position(30, 100);
  setBtn.mouseClicked(addtoDict);

  getBtn = createButton("Get Highest Key");
  getBtn.position(160, 100);
  getBtn.mouseClicked(getHighestKey);

  // Create a Number Dictionary initially
  numDict = createNumberDict(100, 0);
}

function addtoDict() {
  clear();

  let key = int(key_input.value());
  let val = int(val_input.value());

  numDict.set(key, val);

  text("New key-value added to dictionary",
       20, 160);

  text("Key:", 20, 60);
  text("Value:", 160, 60);
  text("Click on the button to add new " +
       "values or get the highest key",
       20, 20);
}

function getHighestKey() {

  // Get the highest key in the dictionary
  let highestKey = numDict.maxKey();

  // Display the highest key
  text("The highest key in the dictionary is: " +
       highestKey, 20, 200);

  text("Key:", 20, 60);
  text("Value:", 160, 60);
  text("Click on the button to add new " +
       "values or get the highest key",
       20, 20);
}

Output:

Example 2:

Javascript

function setup() {
  createCanvas(550, 300);
  textSize(16);

  text("Click on the button to create a " +
       "new dictionary and get the highest key",
       20, 20);

  setBtn =
    createButton("Create random dictionary");
  setBtn.position(30, 40);
  setBtn.mouseClicked(createNewDict);

  getBtn = createButton("Get Highest Key");
  getBtn.position(300, 40);
  getBtn.mouseClicked(getHighestKey);
}

function createNewDict() {
  clear();

  // Create an object with random values
  let obj = {};
  for (let i = 0; i < 5; i++) {
    let rk = ceil(Math.random() * 100);
    let rn = floor(Math.random() * 100);
    obj[rk] = rn;

    text("Key: " + rk + " : Value: " +
         rn, 40, 120 + 20 * i);
  }

  // Create a number dict using
  // the above values
  numDict = createNumberDict(obj);

  text("New Dictionary created with values",
       20, 80);

  text("Click on the button to create a " +
       "new dictionary and get the highest key",
       20, 20);
}

function getHighestKey() {

  // Get the highest key in the dictionary
  let highestKey = numDict.maxKey();

  // Display the lowest key
  text("The highest key in the dictionary is: " +
       highestKey, 20, 240);

  text("Click on the button to create a " +
       "new dictionary and get the highest key",
       20, 20);
}

Output:

Online editor: https://editor.p5js.org/
Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/amp/
Reference: https://p5js.org/reference/#/p5.NumberDict/maxKey