如何防止数组中的空字符串计为长度的一部分?

Question

所以，我有一个我获取的JSON文件。数组syllables最多可以容纳字符串。 但是，当我省略(例如(2 个单词时，我最终会得到 2 个单词和 2 个空字符串。但是在我的前端，当我尝试创建检查时，它仍然需要 4 个"字符串"。所以 2 个单词 + 2 倍的键"输入"，然后说length等于我的 JSON。但是我希望空字符串不是length的一部分。

我的JSON是什么样子的(我举了一个包含更多单词和更多syllables数组的示例(：

{
"main_object": {
"id": "5",
"getExerciseTitle": "TestFor",
"language": "nl_NL",
"application": "lettergrepen",
"main_object": {
"title": "TestFor",
"language": "nl_NL",
"exercises": [
{
"word": "test",
"syllables": [
"test01",
"test02",
"test03",
""
]
},
{
"word": "tesst",
"syllables": [
"test11",
"test12",
"",
""
]
}
]
},
"dataType": "json"
}
}

可能导致此问题的代码段：

$.map(exercise.syllables, function (syllable, j) {
// Code to check if the syllable exists and is not an empty string
if (!syllable || !syllable.trim().length) {
// If it doesn't exist or is an empty string, return early without creating/appending elements
return;
}
var innerSylCol = $('<div/>', {
class: 'col-md-3 inputSyllables'
});
var sylInput = $('<input/>', {
'type': 'text',
'class': 'form-control syl-input',
'name':  +c++,
'id': +idsyll++
}).on('keyup', function() {
var cValue = $(this).val();
if (cValue === syllable) {
correctSylls.push(cValue);
console.log(correctSylls);
}
if (exercise.syllables.length === correctSylls.length) {
$(this).closest('.syll-row').find('input.syl-input').addClass('btn btn-success').removeClass('form-control');
}
});

整个代码的外观：

function createExercise(json) {
const exercises = json.main_object.main_object.exercises;
var exerciseArea = $('<div/>', {
id: 'exerciseField',
'class': 'col-md-12'
});
$.map(exercises, function (exercise, i) {
var exer = $('<div/>', {
'class': 'row form-group',
'id': +idRow++
})
var colLeft = $('<div/>', {
'class': 'col-md-3'
});
var row = $('<div/>', {
'class': 'row'
});
var audCol = $('<div>', {
class: 'col-md-3 audioButton'
}).append(getAudioForWords());
var wordCol = $('<div>', {
class: 'col-md-9 ExerciseWordFontSize exerciseWord',
'id': 'wordInput[' + ID123 + ']', // note to self: the brackets will need to be escaped in later DOM queries
text: exercise.word
});
row.append(audCol, wordCol);
colLeft.append(row);
var sylCol = $('<div>', {
class: 'col-md-9'
});
var sylRow = $('<div/>', {
class: 'row syll-row'
});
function getFilterEmptyString() {
var filtered = syllables.filter(function(str) {
return str.trim()
});
console.log(filtered);
}
var correctSylls = [];
$.map(exercise.syllables, function (syllable, j) {
// Code to check if the syllable exists and is not an empty string
if (!syllable || !syllable.trim().length) {
// If it doesn't exist or is an empty string, return early without creating/appending elements
return;
}
var innerSylCol = $('<div/>', {
class: 'col-md-3 inputSyllables'
});
var sylInput = $('<input/>', {
'type': 'text',
'class': 'form-control syl-input',
'name':  +c++,
'id': +idsyll++
}).on('keyup', function() {
var cValue = $(this).val();
if (cValue === syllable) {
correctSylls.push(cValue);
console.log(correctSylls);
}
if (exercise.syllables.length === correctSylls.length) {
$(this).closest('.syll-row').find('input.syl-input').addClass('btn btn-success').removeClass('form-control');
}
});
innerSylCol.append(sylInput);
sylRow.append(innerSylCol);
});
idsyll = 0;
sylCol.append(sylRow);
exer.append(colLeft, sylCol);
exerciseArea.append(exer);
});
return exerciseArea;
}

我在想什么，但不完全确定：循环不能做到这一点吗？

注意：变量已经声明等。我试图放入尽可能多的代码，这些代码只是与这个问题有关。

Answer 1

您可以通过检查真实值来计算它们。

var syllables = ["test11", "test12", "", ""],
count = syllables.reduce((c, s) => c + Boolean(s), 0);

console.log(count);

或者创建一个新数组，如果以后需要并取长度

var syllables = ["test11", "test12", "", ""],
truthy = syllables.filter(Boolean);

console.log(truthy.length);
console.log(truthy);