diff --git a/1-js/05-data-types/09-keys-values-entries/article.md b/1-js/05-data-types/09-keys-values-entries/article.md index 28c48a53..76b43d9a 100644 --- a/1-js/05-data-types/09-keys-values-entries/article.md +++ b/1-js/05-data-types/09-keys-values-entries/article.md @@ -77,7 +77,7 @@ Objects lack many methods that exist for arrays, e.g. `map`, `filter` and others If we'd like to apply them, then we can use `Object.entries` followed by `Object.fromEntries`: 1. Use `Object.entries(obj)` to get an array of key/value pairs from `obj`. -2. Use array methods on that array, e.g. `map`. +2. Use array methods on that array, e.g. `map`, to transform key/value pairs. 3. Use `Object.fromEntries(array)` on the resulting array to turn it back into an object. For example, we have an object with prices, and would like to double them: @@ -91,12 +91,13 @@ let prices = { *!* let doublePrices = Object.fromEntries( - // convert to array, map, and then fromEntries gives back the object - Object.entries(prices).map(([key, value]) => [key, value * 2]) + // convert prices to array, map key/value pairs into another pair + // and then fromEntries gives back the object + Object.entries(prices).map(entry => [entry[0], entry[1] * 2]) ); */!* alert(doublePrices.meat); // 8 ``` -It may look difficult at first sight, but becomes easy to understand after you use it once or twice. We can make powerful chains of transforms this way. +It may look difficult at first sight, but becomes easy to understand after you use it once or twice. We can make powerful chains of transforms this way.