javascript 使用 UnderscoreJS 从数组中删除项目

Remove an item from array using UnderscoreJS

提问by climboid

Say I have this code

说我有这个代码

var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];

and I want to remove the item with id = 3 from the array. Is there a way of doing this without splicing? Maye something using underscore or something like that?

Thanks!

我想从数组中删除 id = 3 的项目。有没有不拼接的方法？Maye 使用下划线或类似的东西？

谢谢！

回答by Felix Kling

Just using plain JavaScript, this has been answered already: remove objects from array by object property.

只使用普通的 JavaScript，这已经得到了回答：通过对象属性从数组中删除对象。

Using underscore.js, you could combine .findWherewith .without:

使用underscore.js，你可以结合.findWhere使用.without：

var arr = [{
  id: 1,
  name: 'a'
}, {
  id: 2,
  name: 'b'
}, {
  id: 3,
  name: 'c'
}];

//substract third
arr = _.without(arr, _.findWhere(arr, {
  id: 3
}));
console.log(arr);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

Although, since you are creating a new array in this case anyway, you could simply use _.filteror the native Array.prototype.filterfunction (just like shown in the other question). Then you would only iterate over array once instead of potentially twice like here.

尽管如此，由于您在这种情况下无论如何要创建一个新数组，您可以简单地使用_.filteror 本地Array.prototype.filter函数（就像另一个问题中所示）。然后你只会迭代数组一次，而不是像这里那样可能迭代两次。

If you want to modify the array in-place, you have to use .splice. This is also shown in the other question and undescore doesn't seem to provide any useful function for that.

如果要就地修改数组，则必须使用.splice. 这也显示在另一个问题中，并且 undescore 似乎没有为此提供任何有用的功能。

回答by Sushanth --

You can use Underscore .filter

您可以使用下划线 .filter

    var arr = [{
      id: 1,
      name: 'a'
    }, {
      id: 2,
      name: 'b'
    }, {
      id: 3,
      name: 'c'
    }];

    var filtered = _(arr).filter(function(item) {
         return item.id !== 3
    });

Can also be written as:

也可以写成：

var filtered = arr.filter(function(item) {
    return item.id !== 3
});

var filtered = _.filter(arr, function(item) {
    return item.id !== 3
});

Check Fiddle

检查小提琴

You can also use .reject

你也可以使用 .reject

回答by greenafrican

Use Underscore _.reject():

使用下划线_.reject()：

arr = _.reject(arr, function(d){ return d.id === 3; });

回答by PeteGO

Underscore has a _without()method perfect for removing an item from an array, especially if you have the object to remove.

Underscore有一个_without()方法非常适合从数组中删除一个项目，特别是如果你有要删除的对象。

Returns a copy of the array with all instances of the values removed.

返回数组的副本，其中删除了所有值的实例。

_.without(["bob", "sam", "fred"], "sam");

=> ["bob", "fred"]

Works with more complex objects too.

也适用于更复杂的对象。

var bob = { Name: "Bob", Age: 35 };
var sam = { Name: "Sam", Age: 19 };
var fred = { Name: "Fred", Age: 50 };

var people = [bob, sam, fred]

_.without(people, sam);

=> [{ Name: "Bob", Age: 35 }, { Name: "Fred", Age: 50 }];

If you don't have the item to remove, just a property of it, you can use _.findWhereand then _.without.

如果您没有要删除的项目，只有它的一个属性，您可以使用_.findWhere然后_.without。

回答by Srihari Sridharan

Please exercise care if you are filtering strings and looking for case insensitive filters. _.without() is case sensitive. You can also use _.reject() as shown below.

如果您正在过滤字符串并寻找不区分大小写的过滤器，请小心。_.without() 区分大小写。您还可以使用 _.reject() ，如下所示。

var arr = ["test","test1","test2"];

var filtered = _.filter(arr, function(arrItem) {
    return arrItem.toLowerCase() !== "TEST".toLowerCase();
});
console.log(filtered);
// ["test1", "test2"]

var filtered1 = _.without(arr,"TEST");
console.log(filtered1);
// ["test", "test1", "test2"]

var filtered2 = _.reject(arr, function(arrItem){ 
    return arrItem.toLowerCase() === "TEST".toLowerCase();
});
console.log(filtered2);
// ["test1", "test2"]

回答by Sajjad Shirazy

Other answers create a new copy of the array, if you want to modify the array in place you can use:

其他答案创建数组的新副本，如果您想就地修改数组，您可以使用：

arr.splice(_.findIndex(arr, { id: 3 }), 1);

But that assumes that the element will always be found inside the array (because if is not found it will still remove the last element). To be safe you can use:

但这假设元素将始终在数组中找到（因为如果未找到它仍将删除最后一个元素）。为安全起见，您可以使用：

var index = _.findIndex(arr, { id: 3 });
if (index > -1) {
    arr.splice(index, 1);
}

回答by BlackBeard

Use can use plain JavaScript's Array#filtermethod like this:

使用可以像这样使用纯 JavaScript的Array#filter方法：

var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];

var filteredArr = arr.filter(obj => obj.id != 3);

console.log(filteredArr);

Or, use Array#reduceand Array#concatmethods like this:

或者，使用Array#reduce和Array#concat方法如下：

var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];

var reducedArr = arr.reduce((accumulator, currObj) => {
  return (currObj.id != 3) ? accumulator.concat(currObj) : accumulator;
}, []);

console.log(reducedArr);

NOTE:

笔记：

• Both of these are pure functional approach (i.e.they don't modify the existing array).
• No, external library is required in these approach (Vanilla JavaScript is enough).

• 这两种方法都是纯函数式方法（即它们不修改现有数组）。
• 不，这些方法需要外部库（Vanilla JavaScript 就足够了）。

回答by Nadeem

or another handy way:

或其他方便的方式：

_.omit(arr, _.findWhere(arr, {id: 3}));

my 2 cents

我的 2 美分

回答by Anand Tamizh

By Using underscore.js

通过使用 underscore.js

var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];

var resultArr = _.reject(arr,{id:3});

console.log(resultArr);

The result will be :: [{id:1name:'a'},{id:2,name:'c'}]

结果将是 :: [{id:1name:'a'},{id:2,name:'c'}]

回答by Bastin Robin

I used to try this method

我曾经尝试过这个方法

_.filter(data, function(d) { return d.name != 'a' });

There might be better methods too like the above solutions provided by users

可能还有更好的方法，比如用户提供的上述解决方案