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

Using Iterator Protocol with Custom Class

Using Array.prototype.reduce and Symbol.iterator

Array.prototype.entries and Symbol.iterator are used to create a custom iterator class that skips entries with empty values.

Example: The below code shows how to create custom iterator using above-discussed method that skips empty values.

Javascript

class SkipEmptyValues {
    constructor(array) {
        this.entries = array.entries();
    }
 
    [Symbol.iterator]() {
        return {
            next: () => {
                let entry = this.entries.next();
                while (!entry.done && entry.value[1] === '') {
                    entry = this.entries.next();
                }
                return entry;
            },
        };
    }
}
 
const myArray = ['GFG', '', 3, '', 'JavaScript'];
const iterator = new SkipEmptyValues(myArray);
 
for (let value of iterator) {
    console.log(value);
}

Output

[ 0, 'GFG' ]
[ 2, 3 ]
[ 4, 'JavaScript' ]

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: