How to remove empty values from an array

Short answer

filter(Boolean) keeps only truthy values. It removes null, undefined, empty strings, 0, false and NaN:

const values = ['a', '', null, 'b', undefined, 0, 'c'];
 
console.log(values.filter(Boolean));

Output:

[
  "a",
  "b",
  "c"
]

Keep zeros

If 0 and false are real data, remove only null, undefined and empty strings:

const values = [0, '', null, 5, undefined, false];
const clean = values.filter((value) => value !== null && value !== undefined && value !== '');
 
console.log(JSON.stringify(clean));

Output:

[0,5,false]

Strings of spaces

Trim strings first if spaces should count as empty:

const tags = ['js', '  ', 'css', ''];
 
console.log(tags.map((tag) => tag.trim()).filter(Boolean).join(', '));

Output:

js, css

Common mistake

filter(Boolean) also removes zeros, which is often a bug in lists of numbers:

console.log([3, 0, 7].filter(Boolean).join(', '));

Output:

3, 7

Thanks for reading!

Short answer

Keep zeros

Strings of spaces

Common mistake

Functions used in this recipe

Thanks for reading!