CODEWITHSUNDEEP
javascriptarrays
Little Ball
Little Ball

Reputation: 5768

Remove empty elements in 2 different arrays in javascript

I have 2 arrays, one of which is filled with elements and the other has empty elements, eg:

let arr1 = ['apples', 'bananas', 'oranges', 'strawberries', 'blueberries', 'pineapple']
let arr2 = [1,,3,,,4]

How do I remove both bananas, strawberries and blueberries and the empty element in arr2, should look something like this:

let arr1 = ['apples', 'oranges', 'pineapple']
let arr2 = [1,3,4]

edit: added more elements to the array for scale.

Upvotes: 1

Views: 66

Answers (5)

Arun Prasat
Arun Prasat

Reputation: 360

you can iterate and return only the expected value something like the below snippet

After edit please follow the below snippet

let arr1 = ['apples', 'bananas', 'oranges']
let arr2 = [1, , 3]
var filtered = arr2.filter((item, index) => {
  if (arr2[index] != null) {
    arr1.splice(index, index);
    return true;
  } else {
    return false
  }
});

console.log(filtered);
console.log(arr1);

Upvotes: 1

Sash Sinha
Sash Sinha

Reputation: 22370

You can use Array.prototype.filter():

let arr1 = ['apples', 'bananas', 'oranges', 'strawberries', 'blueberries', 'pineapple'];
let arr2 = [1,,3,,,4];
arr1 = arr1.filter((x, i) => arr2[i] !== undefined);
arr2 = arr2.filter(x => x !== undefined);
console.log(arr1);
console.log(arr2);

Upvotes: 2

anpel
anpel

Reputation: 941

You can use filter()

let arr1 = ['apples', 'bananas', 'oranges', 'strawberries', 'blueberries', 'pineapple']
let arr2 = [1,,3,,,4]

let result = arr1.filter((item, index) => {
    return arr2[index] !== undefined;
});

console.log(result); // Outputs: ["apples", "oranges", "pineapple"]

Check this fiddle.

Upvotes: 1

user14520680
user14520680

Reputation: 

const filterOutItems = (array, itemValue = undefined) {
  if (typeof itemValue == undefined) {
    return array.filter((el) => !!el);
  } else {
    return array.filter((el) => el != itemValue);
  }
}

The filter method will return only the items that satisfy the predicate.

Upvotes: 0

Nina Scholz
Nina Scholz

Reputation: 386620

You could map and filter with true because filter omits sparse items.

let array1 = ['apples', 'bananas', 'oranges'],
    array2 = [1, , 3],
    result1 = array2.map((_, i) => array1[i]).filter(_ => true),
    result2 = array2.filter(_ => true);

console.log(result1);
console.log(result2);

Upvotes: 2

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