How to delete an element from an array with UnderscoreJS

Question

How to delete an element from an array with UnderscoreJS

Here's a scenario:

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

I'm looking to delete the element with id value of 3 from this array. Is there a method to achieve this without using splice? Perhaps utilizing underscore or a similar tool?

Appreciate your help!

javascript underscore.js

Answer 1

Answer №1

If you prefer using plain JavaScript, the solution to removing objects from an array based on object property was already provided in this post: remove objects from array by object property.

Alternatively, if you opt for underscore.js, you can utilize the combination of .findWhere and .without:

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

// exclude third item
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>

However, if you are creating a new array anyway, consider using _.filter or the native Array.prototype.filter function instead (as demonstrated in the linked question). This will result in a more efficient iteration over the array without potentially double traversal.

To modify the array directly (in-place), use .splice, as discussed in the other question. Underscore does not offer a specific function for this purpose.

Answer 2

If you prefer using plain JavaScript, the solution to removing objects from an array based on object property was already provided in this post: remove objects from array by object property.

Alternatively, if you opt for underscore.js, you can utilize the combination of .findWhere and .without:

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

// exclude third item
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>

However, if you are creating a new array anyway, consider using _.filter or the native Array.prototype.filter function instead (as demonstrated in the linked question). This will result in a more efficient iteration over the array without potentially double traversal.

To modify the array directly (in-place), use .splice, as discussed in the other question. Underscore does not offer a specific function for this purpose.

Answer 3

Answer №2

If you want to filter an array using Underscore, you can use the .filter method.

var data = [{
      id: 1,
      name: 'apple'
    }, {
      id: 2,
      name: 'banana'
    }, {
      id: 3,
      name: 'carrot'
    }];

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

An alternate way to achieve the same result is:

var filteredData = data.filter(function(item) {
    return item.id !== 3
});

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

View Fiddle

You can also explore the .reject method for similar functionality.

Answer 4

If you want to filter an array using Underscore, you can use the .filter method.

var data = [{
      id: 1,
      name: 'apple'
    }, {
      id: 2,
      name: 'banana'
    }, {
      id: 3,
      name: 'carrot'
    }];

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

An alternate way to achieve the same result is:

var filteredData = data.filter(function(item) {
    return item.id !== 3
});

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

View Fiddle

You can also explore the .reject method for similar functionality.

Answer 5

Answer №3

Utilize Underscore's _.reject() method:

list = _.reject(list, function(item){ return item.id === 3; });

Answer 6

Utilize Underscore's _.reject() method:

list = _.reject(list, function(item){ return item.id === 3; });

Answer 7

Answer №4

For those looking to efficiently remove items from an array, Underscore offers the _without() method as a perfect solution.

This method returns a modified copy of the original array with specified values removed.

_.without(["apple", "banana", "cherry"], "apple");

=> ["banana", "cherry"]

The flexibility of _without() extends to more complex objects as demonstrated below.

var apple = { Name: "Apple", Price: 1.99 };
var banana = { Name: "Banana", Price: 0.79 };
var cherry = { Name: "Cherry", Price: 3.49 };

var fruits = [apple, banana, cherry]

_.without(fruits, banana);

=> [{ Name: "Apple", Price: 1.99 }, { Name: "Cherry", Price: 3.49 }];

If you only have a property value to identify the item for removal, combining _.findWhere and _.without is another effective approach.

Answer 8

For those looking to efficiently remove items from an array, Underscore offers the _without() method as a perfect solution.

This method returns a modified copy of the original array with specified values removed.

_.without(["apple", "banana", "cherry"], "apple");

=> ["banana", "cherry"]

The flexibility of _without() extends to more complex objects as demonstrated below.

var apple = { Name: "Apple", Price: 1.99 };
var banana = { Name: "Banana", Price: 0.79 };
var cherry = { Name: "Cherry", Price: 3.49 };

var fruits = [apple, banana, cherry]

_.without(fruits, banana);

=> [{ Name: "Apple", Price: 1.99 }, { Name: "Cherry", Price: 3.49 }];

If you only have a property value to identify the item for removal, combining _.findWhere and _.without is another effective approach.

Answer 9

Answer №5

When filtering strings with case insensitivity in mind, it's important to be cautious. The _.without() function is case sensitive, so you may want to consider using _.reject() instead. See the example below for how this can be done:

var array = ["example","example1","example2"];

var filteredArray = _.filter(array, function(item) {
    return item.toLowerCase() !== "EXAMPLE".toLowerCase();
});
console.log(filteredArray);
// ["example1", "example2"]

var filteredArray1 = _.without(array,"EXAMPLE");
console.log(filteredArray1);
// ["example", "example1", "example2"]

var filteredArray2 = _.reject(array, function(item){ 
    return item.toLowerCase() === "EXAMPLE".toLowerCase();
});
console.log(filteredArray2);
// ["example1", "example2"]

Answer 10

When filtering strings with case insensitivity in mind, it's important to be cautious. The _.without() function is case sensitive, so you may want to consider using _.reject() instead. See the example below for how this can be done:

var array = ["example","example1","example2"];

var filteredArray = _.filter(array, function(item) {
    return item.toLowerCase() !== "EXAMPLE".toLowerCase();
});
console.log(filteredArray);
// ["example1", "example2"]

var filteredArray1 = _.without(array,"EXAMPLE");
console.log(filteredArray1);
// ["example", "example1", "example2"]

var filteredArray2 = _.reject(array, function(item){ 
    return item.toLowerCase() === "EXAMPLE".toLowerCase();
});
console.log(filteredArray2);
// ["example1", "example2"]

Answer 11

Answer №6

If you wish to make changes to an array without creating a new copy, you can perform the following operation:

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

However, this method assumes that the element will always be present in the array (as it will remove the last element if not found). For a safer approach, consider using the code snippet below:

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

Answer 12

If you wish to make changes to an array without creating a new copy, you can perform the following operation:

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

However, this method assumes that the element will always be present in the array (as it will remove the last element if not found). For a safer approach, consider using the code snippet below:

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

Answer 13

Answer №7

Here's an alternative method to achieve the same outcome:

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

Just a thought

Answer 14

Here's an alternative method to achieve the same outcome:

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

Just a thought

Answer 15

Answer №8

Utilize the power of plain vanilla JavaScript by leveraging Array#filter method in the following way:

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);

Alternatively, you can opt for Array#reduce and Array#concat methods as shown below:

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);

PLEASE NOTE:

Both of these techniques follow a pure functional approach (i.e. they preserve the original array).
No external libraries are necessary with these strategies (Vanilla JavaScript is sufficient).

Answer 16

Utilize the power of plain vanilla JavaScript by leveraging Array#filter method in the following way:

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);

Alternatively, you can opt for Array#reduce and Array#concat methods as shown below:

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);

PLEASE NOTE:

Both of these techniques follow a pure functional approach (i.e. they preserve the original array).
No external libraries are necessary with these strategies (Vanilla JavaScript is sufficient).

Answer 17

Answer №9

I experimented with this technique in the past

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

Other users have also suggested alternative solutions that may be more effective

Answer 18

I experimented with this technique in the past

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

Other users have also suggested alternative solutions that may be more effective

Answer 19

Answer №10

Utilizing underscore.js

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

var newResult = _.reject(data,{id:3});

console.log(newResult);

The output would be :: [{id:1name:'a'},{id:2,name:'c'}]

Answer 20

Utilizing underscore.js

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

var newResult = _.reject(data,{id:3});

console.log(newResult);

The output would be :: [{id:1name:'a'},{id:2,name:'c'}]

Answer 21

Answer №11

To filter out specific items from an array, you can utilize the reject method from Underscore. The example below demonstrates how to create a new array without the item that matches a certain condition.

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

Answer 22

To filter out specific items from an array, you can utilize the reject method from Underscore. The example below demonstrates how to create a new array without the item that matches a certain condition.

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

Answer 23

Answer №12

Underscore.js is a library that offers:

_.filter(arr);

Answer 24

Underscore.js is a library that offers:

_.filter(arr);

How to delete an element from an array with UnderscoreJS

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Answer №7

Answer №8

Answer №9

Answer №10

Answer №11

Answer №12

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