Returning lengthy words from a string using JavaScript

We are required to write a JavaScript function that takes in a sentence of words and a number. The function should return an array of all words greater than the length specified by the number.

Problem Statement

Input:

const str = 'this is an example of a basic sentence';
const num = 4;

Expected Output:

const output = [ 'example', 'basic', 'sentence' ];

Because these are the only three words with length greater than 4.

Using for Loop

The most straightforward approach is to split the string into words and iterate through them:

const str = 'this is an example of a basic sentence';
const num = 4;

const findLengthy = (str = '', num = 1) => {
    const strArr = str.split(' ');
    const res = [];
    
    for(let i = 0; i < strArr.length; i++){
        const el = strArr[i];
        if(el.length > num){
            res.push(el);
        }
    }
    return res;
};

console.log(findLengthy(str, num));

[ 'example', 'basic', 'sentence' ]

Using Array.filter() Method

A more concise solution using the filter() method:

const str = 'this is an example of a basic sentence';
const num = 4;

const findLengthyWords = (str, num) => {
    return str.split(' ').filter(word => word.length > num);
};

console.log(findLengthyWords(str, num));

[ 'example', 'basic', 'sentence' ]

Using Regular Expressions

For more complex word extraction, you can use regular expressions to handle punctuation:

const str = 'Hello, this is an example! Basic sentence.';
const num = 4;

const findLengthyWordsRegex = (str, num) => {
    const words = str.match(/\b\w+\b/g) || [];
    return words.filter(word => word.length > num);
};

console.log(findLengthyWordsRegex(str, num));

[ 'Hello', 'example', 'Basic', 'sentence' ]

Comparison

Conclusion

Use Array.filter() for clean, readable code when working with simple spaces. For text with punctuation, consider the regex approach to properly extract words.