如何从ejs中数组中的所有对象获取所有使用的值

Question

假设我有一个数组，其中包含“图像”对象。在“图像”中，我有另一个数组，称为“标签”。我有这个来排序图像。但是，我不知道如何在不重复的情况下获取所有“标签”数组中的所有值。

下面是两个“图像”对象和我想要获取的数据的概述。

{
"image1": { //IMAGE OBJECT 1
"path": "/res/img/path",
"name": "Red Car",
"tags": ["Red", "Cars"] //I want both of these values.
},
"image2": { //IMAGE OBJECT 2
    "path": "/res/img/otherpath",
    "name": "Blue Car",
    "tags": ["Blue", "Cars"] //I only want the 'Blue' tag, because 'Cars' would be duplicate.
},
"image3": { //IMAGE OBJECT 3
    "path": "/res/img/otherotherpath",
    "name": "Red Fridge",
    "tags": ["Red", "Fridge"] //I only want the 'Fridge' tag, because 'Red' would be duplicate.
}

有人知道怎么做吗？我不需要确切的代码，只需要概念。我想自己弄清楚代码:)

Answer 1

您可以结合使用 array.map() 和 array.reduce()。

console.log(
  array
    .map(obj => obj.tags) // get all tags
    .flat() // and convert it to one big list
    .reduce((arr, val) => arr.includes(val) ? arr : arr.concat(val), []) // remove duplicates
);

Answer 2

试试这个，

var data = {
"image1": { //IMAGE OBJECT 1
"path": "/res/img/path",
"name": "Red Car",
"tags": ["Red", "Cars"] //I want both of these values.
},
"image2": { //IMAGE OBJECT 2
    "path": "/res/img/otherpath",
    "name": "Blue Car",
    "tags": ["Blue", "Cars"] //I only want the 'Blue' tag, because 'Cars' would be duplicate.
},
"image3": { //IMAGE OBJECT 3
    "path": "/res/img/otherotherpath",
    "name": "Red Fridge",
    "tags": ["Red", "Fridge"] //I only want the 'Fridge' tag, because 'Red' would be duplicate.
}
}
var filteredArray = new Set();

Object.keys(data).forEach((key) => {
    data[key]['tags'].forEach((tag) => {
    filteredArray.add(tag)
  })
});
filteredArray = Array.from(filteredArray).sort();
console.log(filteredArray);

Answer 3

 const colors = ['red', 'green', 'green', 'red', 'blue', 'red', 'blue']
 
 function copyArrayWithNoDupes(array) {
  return Array.from(new Set([...array])).sort();
}
console.log(copyArrayWithNoDupes(colors))

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set

Answer 4

希望这段代码对您有所帮助

var obj = {
"image1": { //IMAGE OBJECT 1
"path": "/res/img/path",
"name": "Red Car",
"tags": ["Red", "Cars"] //I want both of these values.
},
"image2": { //IMAGE OBJECT 2
    "path": "/res/img/otherpath",
    "name": "Blue Car",
    "tags": ["Blue", "Cars"] //I only want the 'Blue' tag, because 'Cars' would be duplicate.
},
"image3": { //IMAGE OBJECT 3
    "path": "/res/img/otherotherpath",
    "name": "Red Fridge",
    "tags": ["Red", "Fridge"] //I only want the 'Fridge' tag, because 'Red' would be duplicate.
}
}
Object.values(obj).flatMap(o=>o.tags).filter((elem, index, self)=>index === self.indexOf(elem))

Answer 5

使用Object.keys

var tags = {
"image1": { //IMAGE OBJECT 1
"path": "/res/img/path",
"name": "Red Car",
"tags": ["Red", "Cars"] //I want both of these values.
},
"image2": { //IMAGE OBJECT 2
    "path": "/res/img/otherpath",
    "name": "Blue Car",
    "tags": ["Blue", "Cars"] //I only want the 'Blue' tag, because 'Cars' would be duplicate.
},
"image3": { //IMAGE OBJECT 3
    "path": "/res/img/otherotherpath",
    "name": "Red Fridge",
    "tags": ["Red", "Fridge"] //I only want the 'Fridge' tag, because 'Red' would be duplicate.
}
}
var filteredTags = new Set();

Object.keys(tags).forEach((key) => {
    tags[key]['tags'].forEach((tag) => {
    filteredTags.add(tag)
  })
});

filteredTags = Array.from(filteredTags).sort();

console.log(filteredTags);

如何从ejs中数组中的所有对象获取所有使用的值

How to get all used values from all objects in array in ejs

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