Remove Empty Elements from an Array in JavaScript

Remove empty elements from an array in Javascript

EDIT: This question was answered almost nine years ago when there were not many useful built-in methods in the Array.prototype.

Now, certainly, I would recommend you to use the filter method.

Take in mind that this method will return you a new array with the elements that pass the criteria of the callback function you provide to it.

For example, if you want to remove null or undefined values:

var array = [0, 1, null, 2, "", 3, undefined, 3,,,,,, 4,, 4,, 5,, 6,,,,];

var filtered = array.filter(function (el) {

  return el != null;

});

console.log(filtered);

How to remove empty array values ( ) from an array?

You could use the filter like:

arr = arr.filter(item => item);

Example:

let arr = ['One', 'Two', '', 'Four', '', ''];
arr = arr.filter(item => item);
console.log(arr);

// Result
// ['One', 'Two', 'Four']

Because an empty string evaluates to boolean false.
It works with all falsy values like 0, false, null, undefined, '', etc.

DEMO

If you want to keep some values like number 0 (zero) you could use item !== undefined. This filters only undefined values. Keep in mind to trim your string or check with regex to ensure empty strings without whitespaces.

How to remove empty trailing values and Carriage Return in JS Array?

I don't think there's any magic bullet here, just a loop checking for the values you want to remove, directly or with a regular expression. For instance, to remove blank strings and "\r":

while (array.length) {                      // Loop while there are still entries
    const last = array[array.length - 1];   // Get the last entry without removing it
    if (last !== "" && last !== "\r") {     // Is this one to remove?
        break;                              // No, stop
    }
    --array.length;                         // Yes, remove and keep looping
}

Live Example:

const array = ['', 'Apple', '', 'Banana', '', 'Guava', '', '', '', '\r'];
while (array.length) {                      // Loop while there are still entries
    const last = array[array.length - 1];   // Get the last entry without removing it
    if (last !== "" && last !== "\r") {     // Is this one to remove?
        break;                              // No, stop
    }
    --array.length;                         // Yes, remove and keep looping
}

console.log(array);

Remove empty values from array of objects only if the value is empty in all objects

If you don't mind mutating the original array object. Here's a solution utilizing some array functions.

let array = [
  { name: 'John', age: '18', address: '' },
  { name: 'George', age: '', address: '' },
  { name: 'Kevin', age: '25', address: '' }
]

Object.keys(array[0])
  .filter(k => array.every(obj => !obj[k]))
  .forEach(k => array.forEach(obj => delete obj[k]));

console.log(array);

Remove empty array from array of objects

• Using Array#map, iterate over the array
• Using Object#entries, get the list of entries for the current object
• Using Array#filter, filter the entries whose value is an empty array
• Using Object#fromEntries, return the current object containing the filtered entries

const arr = [
  {
    "2022-03-10": [
      { "Age": "31", "Last": "Craig", "Name": "Carlos", "Time": "11:00am - 12:00pm", "Type": "Consulta General", "read": false }
    ],
    "2022-03-26": [
      { "Age": "31", "Last": "Craig", "Name": "Carlos", "Time": "11:00am - 12:00pm", "Type": "Follow Up", "read": false }
    ],
    "2022-03-27": [],
    "2022-03-31": [
      { "Age": "31", "Last": "Craig", "Name": "Carlos", "Time": "11:00am - 12:00pm", "Type": "Valoraciones Funcionales", "read": false }
    ]
  }
];

const filtered = arr.map(obj => 
  Object.fromEntries(
    Object.entries(obj).filter(([key, value]) => value.length > 0)
  )
);

console.log(filtered);

---

Related Topics