How to count the words in a String in JavaScript

Count the words in a String #

To count the words in a string:

1. Call the split() method on the string, passing it a string containing a space as a parameter.
2. The split method will return an array of the string's words, on which you can access the length property to get the number of words in the string.

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function countWords(str) {
  const arr = str.split(' ');

  return arr.filter(word => word !== '').length;
}

console.log(countWords('One two three')); // 👉️ 3
console.log(countWords('This   is   a long string')); // 👉️ 5

We created a reusable function, which takes a string as a parameter and returns the number of words in the string.

We use the String.split method and split the string on the spaces.

This returns an array containing the words in the string.

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// 👇️ ['hello', 'world']
console.log('hello world'.split(' '));

// 👇️ ['one', 'two', 'three']
console.log('one two three'.split(' '));

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// 👇️ ['hello', '', 'world']
console.log('hello  world'.split(' '));

// 👇️ ['one', '', 'two', '', 'three']
console.log('one  two  three'.split(' '));

To make sure we don't count empty strings as words, we use the Array.filter method to filter empty strings out, before accessing the length property on the array.

The function we passed to the filter method gets called with each element in the array.

We check if each element is NOT equal to an empty string and if the condition is met, the element gets added to the new array.

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const arr = ['one', '', 'two', ''];

const filtered = arr.filter(element => element !== '');

// 👇️ ['one', 'two']
console.log(filtered);

The last step is to access the length property on the array and get the word count.

Here's the complete example.

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function countWords(str) {
  const arr = str.split(' ');

  return arr.filter(word => word !== '').length;
}

console.log(countWords('Walk the dog')); // 👉️ 3
console.log(countWords('Buy   groceries')); // 👉️ 2

Further Reading #

• Check if String contains only Latin Letters in JavaScript
• How to compare 3 Values in JavaScript