Proxy - JavaScript Challenges

#webdev #javascript #beginners #learning

You can find all the code in this post in the repo Github.

Proxy related challenges

Access negative index

Proxy can intercept operations of objects. We can use it to rewriting or enhancing the behavior of accessing and setting properties.

/**
 * @param {Array} arr
 */

function withNegativeIndex(arr) {
  return new Proxy(arr, {
    get(target, property, receiver) {
      const index = Number(property);

      if (index < 0) {
        property = target.length + index;
      }

      return Reflect.get(target, property, receiver);
    },
  });
}

// Usage example
const fruits = ["apple", "banana", "orange"];
const proxiedFruits = withNegativeIndex(fruits);

console.log(proxiedFruits[-1]); // => 'orange'
console.log(proxiedFruits[-2]); // => 'banana'
console.log(proxiedFruits[-3]); // => 'apple'
console.log(proxiedFruits[0]); // => 'apple'
console.log(proxiedFruits[1]); // => 'banana'
console.log(proxiedFruits[2]); // => 'orange'