p5.js NumberDict maxKey() 方法

p5.js 中 p5.NumberDict 的maxKey()方法用于查找数字字典中的最高键值。键值对是一组相互映射的两个值。可以通过使用该对的键部分查询此字典来访问这些值。数字字典可以存储多个键值对，这些键值对可以使用字典的方法进行访问。

句法：

maxKey()

参数：此函数不接受任何参数。

返回值：它返回一个数字值，它是数字字典中的最高键。

下面的例子说明了 p5.js 中的maxKey() 方法：

示例 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);
}

输出：

示例 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);
}

输出：

在线编辑器： https://editor.p5js.org/
环境设置： https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/
参考： https://p5js.org/reference/#/p5.NumberDict/maxKey