Question

一切都很好，直到我调用函数var picked color = pickColor（）;为止。我已经分别在控制台中运行功能pickColor（）-正常！！！请帮忙!!!

HTML

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="colorGame.css">
    <title>Color Game</title>
</head>

<body>

    <h1>The <span id= "colorDisplay">Great </span> Colors Game!!!</h1>

    <div id="message"></div>

    <div id="container">

        <div class="squares"></div>
        <div class="squares"></div>
        <div class="squares"></div>
        <div class="squares"></div>
        <div class="squares"></div>
        <div class="squares"></div>

    </div>



    <script src = "colorGame.js"></script>
</body>

</html>

CSS

/*Color Games CSS*/


/*General Styles*/

body {

    margin: 0;
    padding:0;

    background-color: #232323;
}

h1{

    color:white;
}

#container {

    width:600px;
    margin: 0 auto;


}

#message {

    color:white;
}


.squares {

    width: 180px;
    height:190px;

    background-color: purple;
    float:left;
    margin-right: 10px;
    margin-bottom: 10px;

    border-radius: 40px;


}

Color Games JavaScript-一切都很好，直到我调用函数var picked color = pickColor（）;为止。我已经分别在控制台中运行功能pickColor（）-正常！！！请帮忙!!!

var colors = [

    "rgb(255, 0, 0)",
    "rgb(255, 255, 0)",
    "rgb(0, 255, 0)",
    "rgb(0, 255, 255)",
    "rgb(0, 0, 255)",
    "rgb(255, 0, 255)"

];

// Variables 

var squares = document.querySelectorAll(".squares");

var pickedColor = pickColor(); 



var colorDisplay = document.getElementById("colorDisplay");

var message = document.getElementById("message");



//Display 

colorDisplay.textContent = pickedColor;

//test

for (var i = 0; i < squares.length; i++) {

    squares[i].style.backgroundColor = colors[i];



    squares[i].addEventListener("click",function(){

        var clickedColor = this.style.backgroundColor;



        if (clickedColor === pickedColor){

            message.textContent = "Right Color";
            changeColors(clickedColor); 


        } else {

            this.style.backgroundColor = "#232323";
            message.textContent = "Try Again";
        }
    });

    function changeColors(color){

        for (i = 0; i < squares.length;  i++){

            squares[i].style.backgroundColor =  color; //
        }
    }

    function pickColor(){

        var random = Math.floor(Math.random() * colors.length );

        return colors[random];
    }


}

Answer 1

在for循环之外定义pickColor和changeColor函数。如果它们在循环中定义，则无法从外部访问它们。

function changeColors(color) {
  for (i = 0; i < squares.length; i++) {
    squares[i].style.backgroundColor = color; //
  }
}
function pickColor() {
  var random = Math.floor(Math.random() * colors.length);
  return colors[random];
}
var colors = [
  "rgb(255, 0, 0)",
  "rgb(255, 255, 0)",
  "rgb(0, 255, 0)",
  "rgb(0, 255, 255)",
  "rgb(0, 0, 255)",
  "rgb(255, 0, 255)"
];
// Variables 
var squares = document.querySelectorAll(".squares");
var pickedColor = pickColor()
var colorDisplay = document.getElementById("colorDisplay");
var message = document.getElementById("message");
//Display 
colorDisplay.textContent = pickedColor;
//test
for (var i = 0; i < squares.length; i++) {
 squares[i].style.backgroundColor = colors[i];
squares[i].addEventListener("click", function() {
    var clickedColor = this.style.backgroundColor;
    if (clickedColor === pickedColor) {
      message.textContent = "Right Color";
      changeColors(clickedColor);
    } else {
      this.style.backgroundColor = "#232323";
      message.textContent = "Try Again";
    }
  });
}

body {
  margin: 0;
  padding: 0;
  background-color: #232323;
}

h1 {
  color: white;
}

#container {
  width: 600px;
  margin: 0 auto;
}

#message {
  color: white;
}

.squares {
  width: 180px;
  height: 190px;
  background-color: purple;
  float: left;
  margin-right: 10px;
  margin-bottom: 10px;
  border-radius: 40px;
}

C

<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" href="colorGame.css">
  <title>Color Game</title>
</head>
<body>
  <h1>The <span id="colorDisplay">Great </span> Colors Game!!!</h1>
  <div id="message"></div>
  <div id="container">
    <div class="squares"></div>
    <div class="squares"></div>
    <div class="squares"></div>
    <div class="squares"></div>
    <div class="squares"></div>
    <div class="squares"></div>
  </div>
</body>
</html>

Answer 2

这是一个范围问题。您正在pickColor循环中定义函数for，因此只能在此循环中定义和使用它。

要解决此问题，只需将函数的定义移到此循环之外，以便您的var pickedColor = pickColor();行可以使用它。

此外，您可能希望oto对changeColors()函数执行相同的操作。像这样：

var colors = [

    "rgb(255, 0, 0)",
    "rgb(255, 255, 0)",
    "rgb(0, 255, 0)",
    "rgb(0, 255, 255)",
    "rgb(0, 0, 255)",
    "rgb(255, 0, 255)"

];

// Variables 

var squares = document.querySelectorAll(".squares");

var pickedColor = pickColor(); 



var colorDisplay = document.getElementById("colorDisplay");

var message = document.getElementById("message");



//Display 

colorDisplay.textContent = pickedColor;

//test

for (var i = 0; i < squares.length; i++) {

    squares[i].style.backgroundColor = colors[i];



    squares[i].addEventListener("click",function(){

        var clickedColor = this.style.backgroundColor;



        if (clickedColor === pickedColor){

            message.textContent = "Right Color";
            changeColors(clickedColor); 


        } else {

            this.style.backgroundColor = "#232323";
            message.textContent = "Try Again";
        }
    });
}

function changeColors(color){

        for (i = 0; i < squares.length;  i++){

            squares[i].style.backgroundColor =  color; //
        }
    }

function pickColor(){

    var random = Math.floor(Math.random() * colors.length );

    return colors[random];
}

Answer 3

据我所知，以下原因请参见评论

var pickedColor = pickColor(); //Global, we're calling here

for (....) {
//codes

function pickColor(){  //Local

    var random = Math.floor(Math.random() * colors.length );

    return colors[random];
}


}

但这仍然是可能的：函数changeColor（）可以像本地函数一样保留在循环中并在本地调用。

function pickColor() {
  var random = Math.floor(Math.random() * colors.length);
  return colors[random];
}  

var colors = [
      "rgb(255, 0, 0)",
      "rgb(255, 255, 0)",
      "rgb(0, 255, 0)",
      "rgb(0, 255, 255)",
      "rgb(0, 0, 255)",
      "rgb(255, 0, 255)"
    ];
    // Variables 
    var squares = document.querySelectorAll(".squares");
    var pickedColor = pickColor()
    var colorDisplay = document.getElementById("colorDisplay");
    var message = document.getElementById("message");
    //Display 
    colorDisplay.textContent = pickedColor;
    //test
    for (var i = 0; i < squares.length; i++) {
     squares[i].style.backgroundColor = colors[i];
    squares[i].addEventListener("click", function() {
        var clickedColor = this.style.backgroundColor;
        if (clickedColor === pickedColor) {
          message.textContent = "Right Color";
          changeColors(clickedColor);
        } else {
          this.style.backgroundColor = "#232323";
          message.textContent = "Try Again";
        }
      });
function changeColors(color) {
  for (i = 0; i < squares.length; i++) {
    squares[i].style.backgroundColor = color; //
  }
}
    }

//未捕获的错误：选择颜色不是功能-我找不到错误

3 个答案: