Question

我试图将数组的每个元素与用户输入进行比较，以便在用户的输入与数组的任何元素不匹配时生成消息。我用来做的代码如下。

var guess_input;
var finished = false;
var colors = ["Aqua", "BurlyWood", "Cornsilk", "DarkGrey", "DarkRed", "Indigo", "LightGrey"];

while (!finished) {
          guess_input = prompt("I'm thinking of one of these colors:\n\n" + "Aqua, BurlyWood, Cornsilk, DarkGrey, DarkRed, Indigo, LightGrey" + "\n\nWhat is the color I'm thinking of?");
          finished = check_guess();
          }
      }
      function check_guess() {

       if (guess_input !=  colors[0] || guess_input != colors[1] || guess_input != colors[2] || guess_input != colors[3])  {
          alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
          return false;
        }
}

这段代码的问题在于，如果我只从数组中选择一个元素，它就可以正常工作。但是当我使用＆＃39; OR＆＃39;操作员，它不起作用。有没有更好的方法来做到这一点？我是java脚本的新手。

谢谢！

Answer 1

您可以使用logical AND运算符&&，因为您需要检查要检查的所有颜色。

if (guess_input != colors[0] && guess_input != colors[1] && guess_input != colors[2] && guess_input != colors[3])  {
     alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
    return false;
}

对于正常工作的代码，您还需要返回true找到找到的颜色。

＆＃13;

var guess_input;
var finished = false;
var colors = ["Aqua", "BurlyWood", "Cornsilk", "DarkGrey", "DarkRed", "Indigo", "LightGrey"];

while (!finished) {
    guess_input = prompt("I'm thinking of one of these colors:\n\n" + "Aqua, BurlyWood, Cornsilk, DarkGrey, DarkRed, Indigo, LightGrey" + "\n\nWhat is the color I'm thinking of?");
    finished = check_guess();
}

function check_guess() {
    if (guess_input != colors[0] && guess_input != colors[1] && guess_input != colors[2] && guess_input != colors[3]) {
        alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
        return false;
    }
    return true; // necessary, otherwise the function returns undefined, which is a falsy value
}

＆＃13;

Answer 2

您需要将guess_input与colours数组中的项进行比较。这是Array.prototype.some()方法的完美工作，true方法返回false或callback，具体取决于var test_guess = colours.some(function(color) { /* 'color' = each item in 'colours' */ return color === guess_input; }); if (test_guess) { /* correct ..... */ } else { /* incorrect .... */ }中定义的条件。例如......

.some()

此处colours开始遍历true数组中的所有项，直到条件返回test_guess。如果猜测与颜色匹配，变量true将为false，否则为protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); try { if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK && null != data) { Uri selectedImage = data.getData(); Intent cropIntent = new Intent("com.android.camera.action.CROP"); cropIntent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, selectedImage); cropIntent.setData(selectedImage); cropIntent.putExtra("crop", "true"); cropIntent.putExtra("aspectX", 7); cropIntent.putExtra("aspectY", 9); cropIntent.putExtra("outputX", 450); cropIntent.putExtra("outputY", 350); cropIntent.putExtra("return-data", false); startActivityForResult(cropIntent, RESULT_CROP_IMG); } else if (requestCode == RESULT_CROP_IMG && resultCode == RESULT_OK && data != null) { Uri cropedImage = data.getData(); String[] filePathColumn = { MediaStore.Images.Media.DATA }; // Get the cursor Cursor cursor = getContentResolver().query(cropedImage, filePathColumn, null, null, null); cursor.moveToFirst(); int columnIndex = cursor.getColumnIndex(filePathColumn[0]); imgDecodableString = cursor.getString(columnIndex); cursor.close(); getSharedPreferences("main", MODE_PRIVATE).edit().putString(Const.CARD_IMAGE, imgDecodableString).apply(); photo.setImageBitmap(BitmapFactory.decodeFile(imgDecodableString)); } } catch (Exception e) { Toast.makeText(this, "Произошла ошибка", Toast.LENGTH_LONG) .show(); } }。

请参阅：Array.prototype.some() @ MDN

将变量与数组元素进行比较（java脚本）

2 个答案: