How to use Array.prototype.reduce and Symbol.iterator In Javascript

Q: How to use Array.prototype.reduce and Symbol.iterator In Javascript

The iterator protocol is implemented using a custom class, which is used to iterate over the array and skipping empty values by controlling the next method.

Using Array.prototype.entries and Symbol.iterator

Array.prototype.reduce is used to build a new array without empty values and implements the Symbol.iterator method on that array.

Example: The below code implemets the above methods to create a custom iterator that skips empty values.

Javascript

class SkipEmptyValuesIterator {
    constructor(array) {
        this.values = array.reduce((acc, value) => {
            if (value !== '') {
                acc.push(value);
            }
            return acc;
        }, []);
    }
 
    [Symbol.iterator]() {
        return this.values[Symbol.iterator]();
    }
}
 
const myArray = ['cat', '', 'ball', '', 'cow'];
const iterator = new SkipEmptyValuesIterator(myArray);
 
for (let value of iterator) {
    console.log(value);
}

Output

cat
ball
cow

How to Create Custom Iterator that Skips Empty Value in JavaScript ?

Iterators are important concepts in the world of programming. They allow developers to traverse and manipulate collections of data more efficiently and flexibly. JavaScript, being a high-level programming language, also supports iterators. You can even create a custom iterator that skips the empty values using the below methods: