Skip to main content
Code Review

Return to Answer

update formatting
Source Link
Sᴀᴍ Onᴇᴌᴀ ♦
Sᴀᴍ Onᴇᴌᴀ ♦
  • 29.6k
  • 16
  • 46
  • 203
varconst result = A2.filter(function(o) {
    return A1.indexOf(o.value) > -1;
});

varconst result = A2.filter(o => A1.includes(o.value));

Try it in this snippet:

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
const result = A2.filter(o => A1.includes(o.value));
console.log('result', result);

If you wanted to use Underscore.js, _.filter()_.filter() and _.includes()_.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
varconst result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck()_.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter()_.filter() and _.includes()_.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
varconst result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>
var result = A2.filter(function(o) {
    return A1.indexOf(o.value) > -1;
});

var result = A2.filter(o => A1.includes(o.value));

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter() and _.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>
const result = A2.filter(function(o) {
    return A1.indexOf(o.value) > -1;
});

const result = A2.filter(o => A1.includes(o.value));

Try it in this snippet:

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
const result = A2.filter(o => A1.includes(o.value));
console.log('result', result);

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
const result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter() and _.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
const result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>
add code samples for completeness
Source Link
Sᴀᴍ Onᴇᴌᴀ ♦
Sᴀᴍ Onᴇᴌᴀ ♦
  • 29.6k
  • 16
  • 46
  • 203

Using Array.prototype.filter() on A2, pass a callback function that returns true when the value at property value is included in A1 by checking A1.indexOf() for a value greater than -1.

var result = A2.filter(function(o) {
    return A1.indexOf(o.value) > -1;
});

This can be simplified to a single line using an ES-6 arrow function and Array.prototype.includes() (Not supported by IE):

var result = A2.filter(o => A1.includes(o.value));

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

Using Array.prototype.filter() on A2, pass a callback function that returns true when the value at property value is included in A1 by checking A1.indexOf() for a value greater than -1.

var result = A2.filter(function(o) {
    return A1.indexOf(o.value) > -1;
});

This can be simplified to a single line using an ES-6 arrow function and Array.prototype.includes() (Not supported by IE):

var result = A2.filter(o => A1.includes(o.value));

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

update explanation
Source Link
Sᴀᴍ Onᴇᴌᴀ ♦
Sᴀᴍ Onᴇᴌᴀ ♦
  • 29.6k
  • 16
  • 46
  • 203

As others have already mentioned, Array.prototype.filter() might be the simplest approach (or Array.prototype.reduce() could also be used but would require more conditional logic). It would typically be slower than the nested for loops because it would be adding additional function calls, but for small data sets it typically wouldn't be noticeable. For example, I did a search on Google for "jsperf filter nested loop" and found this jsPerf test.

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter() and _.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Though some question whether libraries like lodash and underscore are really needed anymore. For a discussion on that, check out this article.

As others have already mentioned, Array.prototype.filter() might be the simplest approach. It would typically be slower than the nested for loops because it would be adding additional function calls, but for small data sets it typically wouldn't be noticeable. For example, I did a search on Google for "jsperf filter nested loop" and found this jsPerf test.

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter() and _.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Though some question whether libraries like lodash and underscore are really needed anymore. For a discussion on that, check out this article.

As others have already mentioned, Array.prototype.filter() might be the simplest approach (or Array.prototype.reduce() could also be used but would require more conditional logic). It would typically be slower than the nested for loops because it would be adding additional function calls, but for small data sets it typically wouldn't be noticeable. For example, I did a search on Google for "jsperf filter nested loop" and found this jsPerf test.

If you wanted to use Underscore.js, _.filter() and _.includes() could be used to filter out any object in A2 without a value for the value property contained in A1. Expand the snippet below for a demonstration.

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

There is an Underscore helper _.pluck() but that is used to collect a value from each item in a collection at a given property (similar to Array.prototype.map().

Lodash also has the same helpers: _.filter() and _.includes().

var A1  = ["1","2","3","4"];

var A2 = [
    {label:"one", value:"1"},
    {label:"two", value:"2"},
    {label:"three", value:"3"},
    {label:"four", value:"4"},
    {label:"five", value:"5"},
    {label:"six", value:"6"},
];
var result = _.filter(A2, function(o) { return _.includes(A1, o.value);});
console.log('result', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Though some question whether libraries like lodash and underscore are really needed anymore. For a discussion on that, check out this article.

Source Link
Sᴀᴍ Onᴇᴌᴀ ♦
Sᴀᴍ Onᴇᴌᴀ ♦
  • 29.6k
  • 16
  • 46
  • 203