diff --git a/README.md b/README.md index 94145e6ee..3189f39ca 100644 --- a/README.md +++ b/README.md @@ -98,6 +98,8 @@ average(1, 2, 3);
View contents +* [`bifurcate`](#bifurcate) +* [`bifurcateBy`](#bifurcateby) * [`chunk`](#chunk) * [`compact`](#compact) * [`countBy`](#countby) @@ -761,6 +763,52 @@ const unary = fn => val => fn(val); --- ## 📚 Array +### bifurcate + +Splits values into two groups. If an element in `filter` is truthy, the corresponding element in the collection belongs to the first group; otherwise, it belongs to the second group. + +Use `Array.reduce()` and `Array.push()` to add elements to groups, based on `filter`. + +```js +const bifurcate = (arr, filter) => + arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [[], []]); +``` + +
+Examples + +```js +bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true]); // [ ['beep', 'boop', 'bar'], ['foo'] ] +``` + +
+ +
[⬆ Back to top](#table-of-contents) + + +### bifurcateBy + +Splits values into two groups according to a predicate function, which specifies which group an element in the input collection belongs to. If the predicate function returns a truthy value, the collection element belongs to the first group; otherwise, it belongs to the second group. + +Use `Array.reduce()` and `Array.push()` to add elements to groups, based on the value returned by `fn` for each element. + +```js +const bifurcateBy = (arr, fn) => + arr.reduce((acc, val, i) => (acc[fn(val, i) ? 0 : 1].push(val), acc), [[], []]); +``` + +
+Examples + +```js +bifurcateBy(['beep', 'boop', 'foo', 'bar'], x => x[0] === 'b'); // [ ['beep', 'boop', 'bar'], ['foo'] ] +``` + +
+ +
[⬆ Back to top](#table-of-contents) + + ### chunk Chunks an array into smaller arrays of a specified size. diff --git a/docs/index.html b/docs/index.html index 6404e8899..1da3415cf 100644 --- a/docs/index.html +++ b/docs/index.html @@ -50,7 +50,7 @@ scrollToTop(); } }, false); - }

logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.

 

Adapter

ary

Creates a function that accepts up to n arguments, ignoring any additional arguments.

Call the provided function, fn, with up to n arguments, using Array.slice(0,n) and the spread operator (...).

const ary = (fn, n) => (...args) => fn(...args.slice(0, n));
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Adapter
ary
Creates a function that accepts up to n arguments, ignoring any additional arguments.
Call the provided function, fn, with up to n arguments, using Array.slice(0,n) and the spread operator (...).
const ary = (fn, n) => (...args) => fn(...args.slice(0, n));
 
const firstTwoMax = ary(Math.max, 2);
 [[2, 6, 'a'], [8, 4, 6], [10]].map(x => firstTwoMax(...x)); // [6, 8, 10]
 
call
Given a key and a set of arguments, call them when given a context. Primarily useful in composition.
Use a closure to call a stored key with stored arguments.
const call = (key, ...args) => context => context[key](...args);
@@ -123,7 +123,13 @@ Object.assig
 arrayMax([1, 2, 3]); // 3
 
unary
Creates a function that accepts up to one argument, ignoring any additional arguments.
Call the provided function, fn, with just the first argument given.
const unary = fn => val => fn(val);
 
['6', '8', '10'].map(unary(parseInt)); // [6, 8, 10]
-
Array
chunk
Chunks an array into smaller arrays of a specified size.
Use Array.from() to create a new array, that fits the number of chunks that will be produced. Use Array.slice() to map each element of the new array to a chunk the length of size. If the original array can't be split evenly, the final chunk will contain the remaining elements.
const chunk = (arr, size) =>
+
Array
bifurcate
Splits values into two groups. If an element in filter is truthy, the corresponding element in the collection belongs to the first group; otherwise, it belongs to the second group.
Use Array.reduce() and Array.push() to add elements to groups, based on filter.
const bifurcate = (arr, filter) =>
+  arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [[], []]);
+
bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true]); // [ ['beep', 'boop', 'bar'], ['foo'] ]
+
bifurcateBy
Splits values into two groups according to a predicate function, which specifies which group an element in the input collection belongs to. If the predicate function returns a truthy value, the collection element belongs to the first group; otherwise, it belongs to the second group.
Use Array.reduce() and Array.push() to add elements to groups, based on the value returned by fn for each element.
const bifurcateBy = (arr, fn) =>
+  arr.reduce((acc, val, i) => (acc[fn(val, i) ? 0 : 1].push(val), acc), [[], []]);
+
bifurcateBy(['beep', 'boop', 'foo', 'bar'], x => x[0] === 'b'); // [ ['beep', 'boop', 'bar'], ['foo'] ]
+
chunk
Chunks an array into smaller arrays of a specified size.
Use Array.from() to create a new array, that fits the number of chunks that will be produced. Use Array.slice() to map each element of the new array to a chunk the length of size. If the original array can't be split evenly, the final chunk will contain the remaining elements.
const chunk = (arr, size) =>
   Array.from({ length: Math.ceil(arr.length / size) }, (v, i) =>
     arr.slice(i * size, i * size + size)
   );
diff --git a/snippets/bifurcate.md b/snippets/bifurcate.md
index 4177c9483..2e124711f 100644
--- a/snippets/bifurcate.md
+++ b/snippets/bifurcate.md
@@ -6,12 +6,9 @@ Use `Array.reduce()` and `Array.push()` to add elements to groups, based on `fil
 
 ```js
 const bifurcate = (arr, filter) =>
-  arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [
-    [],
-    [],
-  ]);
+  arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [[], []]);
 ```
 
 ```js
-bifurcate([ 'beep', 'boop', 'foo', 'bar' ], [ true, true, false, true ]); // [ ['beep', 'boop', 'bar'], ['foo'] ]
+bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true]); // [ ['beep', 'boop', 'bar'], ['foo'] ]
 ```
diff --git a/snippets/bifurcateBy.md b/snippets/bifurcateBy.md
index 23f81b06f..46a00116f 100644
--- a/snippets/bifurcateBy.md
+++ b/snippets/bifurcateBy.md
@@ -6,12 +6,9 @@ Use `Array.reduce()` and `Array.push()` to add elements to groups, based on the
 
 ```js
 const bifurcateBy = (arr, fn) =>
-  arr.reduce((acc, val, i) => (acc[fn(val, i) ? 0 : 1].push(val), acc), [
-    [],
-    [],
-  ]);
+  arr.reduce((acc, val, i) => (acc[fn(val, i) ? 0 : 1].push(val), acc), [[], []]);
 ```
 
 ```js
-bifurcateBy([ 'beep', 'boop', 'foo', 'bar' ], x => x[0] === 'b'); // [ ['beep', 'boop', 'bar'], ['foo'] ]
+bifurcateBy(['beep', 'boop', 'foo', 'bar'], x => x[0] === 'b'); // [ ['beep', 'boop', 'bar'], ['foo'] ]
 ```