使用p5js和javascript，当发送一个字符串时，我的函数可以移动，但当发送一个包含字符串的变量时，却不能移动。

Question

使用被称为p5与javascript的库，我试图使游戏蛇，但它根本无法工作.正如标题中所描述的那样，只有当我给移动函数一个参数，如 "DOWN "时，它才会移动，但当我给它包含值 "DOWN "的变量方向时，它不会移动。

let fr = 5

function setup() {
  frameRate(fr)
  createCanvas(400, 400);
}

x1 = 201
y1 = 201
direction = "NONE"

function move(direction) {
  if (direction === "UP") {
    y1 = y1 - 20
  }
  else if (direction === "DOWN") {
    y1 = y1 + 20
  }
  else if (direction === "LEFT") {
    x1 = x1 - 20
  }
  else if (direction === "RIGHT") {
    x1 = x1 + 20
  }
}

function draw() {
  let c = color('#1cb82e')
  direction = "down"
  background(0);
  square(x1,y1,18);
    fill(c);
  move(direction);
}

function keyPressed() {
  var validKeys = [37,38,39,40]
  var dict = {
    37:"LEFT",
    38:"UP",
    39:"RIGHT",
    40:"DOWN"
  }
  if (validKeys.includes(keyCode) === true) {
    direction = dict[keyCode];
  }
  print(dict[keyCode])
}

有谁能帮我解决这个问题吗，谢谢！！编辑：如果还有人想使用网络编辑器，这里是链接。https:/editor.p5js.org。

Answer 1

你可以使用你的全局 direction 变量，而不是在你的 move 职能。

let fr = 5

function setup() {
  frameRate(fr)
  createCanvas(400, 400);
}

x1 = 201
y1 = 201
direction = "NONE"

function move() {
  if (direction === "UP") {
    y1 = y1 - 20
  }
  else if (direction === "DOWN") {
    y1 = y1 + 20
  }
  else if (direction === "LEFT") {
    x1 = x1 - 20
  }
  else if (direction === "RIGHT") {
    x1 = x1 + 20
  }
}

function draw() {
  let c = color('#1cb82e')
  background(0);
  square(x1,y1,18);
    fill(c);
  move();
}

function keyPressed() {
  var validKeys = [37,38,39,40]
  var dict = {
    37:"LEFT",
    38:"UP",
    39:"RIGHT",
    40:"DOWN"
  }
  if (validKeys.includes(keyCode) === true) {
    direction = dict[keyCode];
  }
  print(dict[keyCode])
}