我正在开发一个项目，我想创建一个名为full_day[]的数组，在通过time_plan[]后，它与数组day_schedule()的长度完全相等。
这是我的代码：
function day_schedule(){
var time_plan = [{"lesson_start":"08:00","lesson_end":"09:00"},{"lesson_start":"09:00","lesson_end":"10:00"},{"lesson_start":"10:00","lesson_end":"11:00"},{"lesson_start":"11:00","lesson_end":"12:00"},{"lesson_start":"12:00","lesson_end":"13:00"},{"lesson_start":"13:00","lesson_end":"13:30"},{"lesson_start":"13:30","lesson_end":"14:30"}];
var day = [{"subject_name":"Math-1","lesson_start":"08:00","lesson_end":"09:00"},{"subject_name":"Phy","lesson_start":"11:00","lesson_end":"12:00"},{"subject_name":"Engl","lesson_start":"12:00","lesson_end":"13:00"}];
var key1 = 'lesson_start';
var key2 = 'lesson_end';
var full_day = [];
for (var d = 0; d < day.length; d++) {
var start_time = day[d].lesson_start;
var end_time = day[d].lesson_end;
for (var i = 0; i < time_plan.length; i++) {
var search_key = time_plan[i][key1] == start_time && time_plan[i][key2] == end_time;
if (search_key == true) {
document.writeln('day matched == ' + day[d],'<br>');
full_day.push(day[d]);
} else {
full_day.push({
lesson_start: ' ',
lesson_end: ' ',
subject_name: ' '
});
}
}
console.log('full day',full_day.length, full_day);
}
}
day_schedule();
我期待
的结果full day 7 [
{
"subject_name": "Math-1",
"lesson_start": "08:00",
"lesson_end": "09:00"
},
{
"lesson_start": " ",
"lesson_end": " ",
"subject_name": " "
},
{
"lesson_start": " ",
"lesson_end": " ",
"subject_name": " "
},
{
"subject_name": "Phy",
"lesson_start": "11:00",
"lesson_end": "12:00"
},
{
"subject_name": "Engl",
"lesson_start": "12:00",
"lesson_end": "13:00"
},
{
"lesson_start": " ",
"lesson_end": " ",
"subject_name": " "
},
{
"lesson_start": " ",
"lesson_end": " ",
"subject_name": " "
}
];
但我不知道该怎么做。
答案 0 :(得分：1)
如果您希望time_plan尺寸与day相匹配，那么您的迭代完全错误。
您在代码中执行的操作是迭代full_day中的每个元素（3个元素），并为这些元素中的每个元素为time_plan中的每个元素添加一个对象element（ 7个要素）。
所以你得到的是：
day中的full_day element您向day添加了7个对象（7个元素）full_day中的Secon element您将另外7个对象添加到day（14个元素）full_day中的第三个function day_schedule(){
var time_plan = [{"lesson_start":"08:00","lesson_end":"09:00"},
{"lesson_start":"09:00","lesson_end":"10:00"},
{"lesson_start":"10:00","lesson_end":"11:00"},
{"lesson_start":"11:00","lesson_end":"12:00"},
{"lesson_start":"12:00","lesson_end":"13:00"},
{"lesson_start":"13:00","lesson_end":"13:30"},
{"lesson_start":"13:30","lesson_end":"14:30"}];
var day =[{
"subject_name":"Math1",
"lesson_start":"08:00",
"lesson_end":"09:00"
},
{
"subject_name":"Phy",
"lesson_start":"11:00",
"lesson_end":"12:00"
},
{
"subject_name":"Engl",
"lesson_start":"12:00",
"lesson_end":"13:00"
}];
var key1 = 'lesson_start';
var key2 = 'lesson_end';
var full_day = [];
for (var tp = 0; tp < time_plan.length; tp++) {
var start_time = time_plan[tp].lesson_start;
var end_time = time_plan[tp].lesson_end;
var lesson = {
lesson_start: ' ',
lesson_end: ' ',
subject_name: ' '
};
for (var i = 0; i < day.length; i++) {
var search_key = day[i][key1] == start_time && day[i][key2] == end_time;
if (search_key == true) {
lesson = day[i]
}
}
full_day.push(lesson)
}
console.log('full day',full_day.length, full_day);
}
day_schedule();您再次将7个对象添加到Array（21个元素）如果你想保留你所使用的逻辑，我建议你反过来转动你的循环：
find()
如您所见，这给出了所需的输出。
现在，我们还可以修改代码以使其更漂亮并使用一些有用的JavaScript function day_schedule(){
var time_plan = [{"lesson_start":"08:00","lesson_end":"09:00"},
{"lesson_start":"09:00","lesson_end":"10:00"},
{"lesson_start":"10:00","lesson_end":"11:00"},
{"lesson_start":"11:00","lesson_end":"12:00"},
{"lesson_start":"12:00","lesson_end":"13:00"},
{"lesson_start":"13:00","lesson_end":"13:30"},
{"lesson_start":"13:30","lesson_end":"14:30"}
];
var day =[{
"subject_name":"Math1",
"lesson_start":"08:00",
"lesson_end":"09:00"
},
{
"subject_name":"Phy",
"lesson_start":"11:00",
"lesson_end":"12:00"
},
{
"subject_name":"Engl",
"lesson_start":"12:00",
"lesson_end":"13:00"
}];
var full_day = [];
// Use foreach instead of regular for when you iterate arrays
for (tp in time_plan) {
var plan = time_plan[tp]
var start_time = plan.lesson_start;
var end_time = plan.lesson_end;
// Use this function to find a suitable lesson given start and end times
var lesson = day.find(function(d) {
var start_matches = d.lesson_start == start_time;
var end_matches = d.lesson_end == end_time;
var matches = start_matches && end_matches;
return start_matches && end_matches;
}) || { // ... or assing a default empty value
lesson_start: ' ',
lesson_end: ' ',
subject_name: ' '
};
full_day.push(lesson)
}
console.log('full day',full_day.length, full_day);
}
day_schedule();函数，例如{{1}}
{{1}}＆＃13;
希望这有帮助。
答案 1 :(得分：0)
创建另一个函数来解析Object并解析它。
attrgetter(".".join(field.split("__")[:1]), ".".join(field.split("__")[:2]), ".".join(field.split("__")[:3]), ".".join(field.split("__")[:4]))(shipment_instance)
答案 2 :(得分：0)
首先，不要使用document.createElement。这仅适用于页面的第一个渲染，是一个阻塞操作，并且在页面渲染后意外使用将擦除页面。考虑使用DOM操作。 node.appendChild和day将是您的朋友。如果可能的话，避免嵌套循环，这是一个坏习惯。如果可能，请使用相邻的循环。
如果您的最终目标是找到time_plan中找到的day中的主题，那么您可以做的是将array.reduce转换为以时间为关键字的对象day。这是使time_plan项唯一的唯一因素，也是唯一可以从array.map识别它的数据。然后使用time_plan将const time_plan = [{"lesson_start":"08:00","lesson_end":"09:00"},{"lesson_start":"09:00","lesson_end":"10:00"},{"lesson_start":"10:00","lesson_end":"11:00"},{"lesson_start":"11:00","lesson_end":"12:00"},{"lesson_start":"12:00","lesson_end":"13:00"},{"lesson_start":"13:00","lesson_end":"13:30"},{"lesson_start":"13:30","lesson_end":"14:30"}];
const day = [{"subject_name":"Math-1","lesson_start":"08:00","lesson_end":"09:00"},{"subject_name":"Phy","lesson_start":"11:00","lesson_end":"12:00"},{"subject_name":"Engl","lesson_start":"12:00","lesson_end":"13:00"}];
// Convert day into time-day element pairs
// { "08:00-09:00": { "subject_name": "..." }, ... }
const dayMap = day.reduce((c, v) => Object.assign(c, {[`${v.lesson_start}-${v.lesson_end}`] : v }), {});
// Convert time_plan to its corresponding day element using time
// as key.
const full_day = time_plan.map(v => dayMap[`${v.lesson_start}-${v.lesson_end}`]).filter(v => !!v);
console.log(full_day);转换为一系列主题。
这只是简单的数组/对象转换，没什么特别的。
array.filter
full_day末尾有一个day，用于删除没有相应{{1}}项的条目。