diff --git a/1-js/05-data-types/05-array-methods/article.md b/1-js/05-data-types/05-array-methods/article.md index 3afba386..4b198dfd 100644 --- a/1-js/05-data-types/05-array-methods/article.md +++ b/1-js/05-data-types/05-array-methods/article.md @@ -44,7 +44,7 @@ The syntax is: arr.splice(start[, deleteCount, elem1, ..., elemN]) ``` -It modified `arr` starting from the index `start`: removes `deleteCount` elements and then inserts `elem1, ..., elemN` at their place. Returns the array of removed elements. +It modifies `arr` starting from the index `start`: removes `deleteCount` elements and then inserts `elem1, ..., elemN` at their place. Returns the array of removed elements. This method is easy to grasp by examples. @@ -700,7 +700,7 @@ alert(soldiers[1].age); // 23 If in the example above we used `users.filter(army.canJoin)`, then `army.canJoin` would be called as a standalone function, with `this=undefined`, thus leading to an instant error. -A call to `users.filter(army.canJoin, army)` can be replaced with `users.filter(user => army.canJoin(user))`, that does the same. The former is used more often, as it's a bit easier to understand for most people. +A call to `users.filter(army.canJoin, army)` can be replaced with `users.filter(user => army.canJoin(user))`, that does the same. The latter is used more often, as it's a bit easier to understand for most people. ## Summary @@ -711,7 +711,7 @@ A cheat sheet of array methods: - `pop()` -- extracts an item from the end, - `shift()` -- extracts an item from the beginning, - `unshift(...items)` -- adds items to the beginning. - - `splice(pos, deleteCount, ...items)` -- at index `pos` delete `deleteCount` elements and insert `items`. + - `splice(pos, deleteCount, ...items)` -- at index `pos` deletes `deleteCount` elements and inserts `items`. - `slice(start, end)` -- creates a new array, copies elements from index `start` till `end` (not inclusive) into it. - `concat(...items)` -- returns a new array: copies all members of the current one and adds `items` to it. If any of `items` is an array, then its elements are taken. @@ -729,7 +729,7 @@ A cheat sheet of array methods: - `sort(func)` -- sorts the array in-place, then returns it. - `reverse()` -- reverses the array in-place, then returns it. - `split/join` -- convert a string to array and back. - - `reduce(func, initial)` -- calculate a single value over the array by calling `func` for each element and passing an intermediate result between the calls. + - `reduce/reduceRight(func, initial)` -- calculate a single value over the array by calling `func` for each element and passing an intermediate result between the calls. - Additionally: - `Array.isArray(arr)` checks `arr` for being an array. @@ -738,7 +738,7 @@ Please note that methods `sort`, `reverse` and `splice` modify the array itself. These methods are the most used ones, they cover 99% of use cases. But there are few others: -- [arr.some(fn)](mdn:js/Array/some)/[arr.every(fn)](mdn:js/Array/every) checks the array. +- [arr.some(fn)](mdn:js/Array/some)/[arr.every(fn)](mdn:js/Array/every) check the array. The function `fn` is called on each element of the array similar to `map`. If any/all results are `true`, returns `true`, otherwise `false`.