NodeJS按键的值查找数组中的对象[重复]

This question already has an answer here:

这个问题在这里已有答案：

Javascript: How to filter object array based on attributes? 10 answers
Javascript：如何根据属性过滤对象数组？ 10个答案

I am trying to get an object in an array by the value of one of its keys.

我试图通过其中一个键的值获取数组中的对象。

The array:

数组：

var arr = [
        {
            city: 'Amsterdam',
            title: 'This is Amsterdam!'
        },
        {
            city: 'Berlin',
            title: 'This is Berlin!'
        },
        {
            city: 'Budapest',
            title: 'This is Budapest!'
        }
];

I tried doing something like this with lodash but no success.

我尝试用lodash做这样的事情，但没有成功。

var picked = lodash.pickBy(arr, lodash.isEqual('Amsterdam');

and it returns an empty object.

它返回一个空对象。

Any idea on how I can do this the lodash way (if it's even possible)? I can do it the classic way, creating a new array, looping through all objects and pushing the ones matching my criteria to that new array. But is there a way to do it with lodash?

关于如何做到这一点的任何想法lodash方式（如果它甚至可能）？我可以用经典的方式做到这一点，创建一个新的数组，循环遍历所有对象，并将符合我标准的对象推送到新数组。但有没有办法用lodash做到这一点？

This is NOT a duplicate.

这不是重复的。

4 个解决方案

#1

Using lodash and an arrow function, it should be as simple as;

使用lodash和箭头功能，应该如此简单;

var picked = lodash.filter(arr, x => x.city === 'Amsterdam');

...or alternately with object notation;

......或者用对象符号交替;

var picked = lodash.filter(arr, { 'city': 'Amsterdam' } );

Note: The above answer used to be based on pickBy, which as @torazaburo points out below was not a good choice for the use case.

注意：上面的答案过去基于pickBy，正如@torazaburo在下面指出的那样，对于用例来说不是一个好的选择。

#2

You can use Array.prototype.find() with pure javascript:

您可以将Array.prototype.find（）与纯javascript一起使用：

var picked = arr.find(o => o.city === 'Amsterdam');

It is currently not compatible with all browsers, you need to check it in your environment (but it should work in NodeJS).

它目前与所有浏览器不兼容，您需要在您的环境中检查它（但它应该在NodeJS中工作）。

#3

classical way is even simpler

经典的方式更简单

try

尝试

var output = arr.filter(function(value){ return value.city=="Amsterdam";})

#4

You can use Array.filter

您可以使用Array.filter

As correctly pointed by @torazaburo, you do not need ternary operator return item[key]?item[key] === value:false. A simple check return item[key] === value will do fine.

正如@torazaburo正确指出的那样，你不需要三元运算符返回项[key]？item [key] === value：false。一个简单的检查返回项[键] ===值就可以了。

var arr = [{
  city: 'Amsterdam',
  title: 'This is Amsterdam!'
}, {
  city: 'Berlin',
  title: 'This is Berlin!'
}, {
  city: 'Budapest',
  title: 'This is Budapest!'
}];

Array.prototype.findByValueOfObject = function(key, value) {
  return this.filter(function(item) {
    return (item[key] === value);
  });
}

document.write("<pre>" + JSON.stringify(arr.findByValueOfObject("city", "Amsterdam"), 0, 4) + "</pre>");

#1