如果 title
属性存在,我试图覆盖数组中的对象,否则只需将其推送到数组中。我发现了两种方法,我想知道哪一种是首选。
性能并不是真正的问题,但我想知道可变性是否可能是问题,或者只是有更好的方法来做到这一点。
在此片段中,我使用 for 循环来编辑原始数组:
const data = [
{
title: 'AAA',
people: [ 'John', 'Megan',]
},{
title: 'BBB',
people: [ 'Emily', 'Tom']
}
]
// If inputTitle is not on any of data's title it will append not overwrite
// e.g. const inputTitle = 'CCC'
const inputTitle = 'AAA'
const inputPeople = ['Peter', 'Jane']
for (const obj of data) {
if (obj.title === inputTitle) {
obj.people = inputPeople
break
} else {
data.push({
title: inputTitle,
people: inputPeople
})
break
}
}
console.log(data)
这里我使用高阶函数和展开来执行相同的操作:
const data = [
{
title: 'AAA',
people: [ 'John', 'Megan',]
},{
title: 'BBB',
people: [ 'Emily', 'Tom']
}
]
// If inputTitle is not on any of data's title it will append not overwrite
// e.g. const inputTitle = 'CCC'
const inputTitle = 'AAA'
const inputPeople = ['Peter', 'Jane']
let res = []
if (data.some(({ title }) => title === inputTitle)) {
res = data.map(obj => {
if (obj.title === inputTitle)
obj.people = inputPeople
return obj
})
} else {
res = [...data, { title: inputTitle, people: inputPeople}]
}
console.log(res)
在实际任务中,我使用节点从 json 文件中读取 data
数组,并将更改写回其中。
最佳答案
如果这是一个常见的用例,您将在同一数据结构上执行多次,那么您最好使用按标题键控的普通对象,因为这样操作就很简单了。您仍然可以将标题也保留为您拥有的属性。
const data = {
AAA: {
title: 'AAA',
people: [ 'John', 'Megan',]
},
BBB: {
title: 'BBB',
people: [ 'Emily', 'Tom']
}
};
const title = 'AAA';
const people = ['Peter', 'Jane'];
data[title] = { title, people }; // yes, it's that simple then...
console.log(data);
如果你确实需要数组结构,那么你可以考虑暂时切换,然后进行所有操作,然后再回到原来的格式:
let data = [
{
title: 'AAA',
people: [ 'John', 'Megan',]
},
{
title: 'BBB',
people: [ 'Emily', 'Tom']
}
];
const title = 'AAA';
const people = ['Peter', 'Jane'];
// switch to other data structure...
let map = Object.fromEntries(data.map(o => [o.title, o]));
// Manipulate
map[title] = { title, people };
// ...and back:
data = Object.values(map);
console.log(data);
关于javascript - 添加/覆盖数组中的对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/66506863/