diff --git a/README.md b/README.md index c7cfc7723..378d4e04a 100644 --- a/README.md +++ b/README.md @@ -189,6 +189,7 @@ average(1, 2, 3); * [`uniqueElements`](#uniqueelements) * [`uniqueElementsBy`](#uniqueelementsby) * [`uniqueElementsByRight`](#uniqueelementsbyright) +* [`uniqueSymmetricDifference`](#uniquesymmetricdifference) * [`unzip`](#unzip) * [`unzipWith`](#unzipwith-) * [`without`](#without) @@ -2619,7 +2620,7 @@ const stable = stableSort(arr, () => 0); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] ### symmetricDifference -Returns the symmetric difference between two arrays. +Returns the symmetric difference between two arrays, without filtering out duplicate values. Create a `Set` from each array, then use `Array.filter()` on each of them to only keep values not contained in the other. @@ -2635,7 +2636,8 @@ const symmetricDifference = (a, b) => { Examples ```js -symmetricDifference([1, 2, 3], [1, 2, 4]); // [3,4] +symmetricDifference([1, 2, 3], [1, 2, 4]); // [3, 4] +symmetricDifference([1, 2, 2], [1, 3, 1]); // [2, 2, 3] ``` @@ -3025,6 +3027,31 @@ uniqueElementsByRight(
[⬆ Back to top](#table-of-contents) +### uniqueSymmetricDifference + +Returns the unique symmetric difference between two arrays, not containing duplicate values from either array. + +Use `Array.filter()` and `Array.includes()` on each array to remove values contained in the other, then create a `Set` from the results, removing duplicate values. + +```js +const uniqueSymmetricDifference = (a, b) => [ + ...new Set([...a.filter(v => !b.includes(v)), ...b.filter(v => !a.includes(v))]) +]; +``` + +
+Examples + +```js +uniqueSymmetricDifference([1, 2, 3], [1, 2, 4]); // [3, 4] +uniqueSymmetricDifference([1, 2, 2], [1, 3, 1]); // [2, 3] +``` + +
+ +
[⬆ Back to top](#table-of-contents) + + ### unzip Creates an array of arrays, ungrouping the elements in an array produced by [zip](#zip). diff --git a/docs/adapter.html b/docs/adapter.html index bf63e24cb..e0f7d1c64 100644 --- a/docs/adapter.html +++ b/docs/adapter.html @@ -79,7 +79,7 @@ document.getElementById('doc-drawer-checkbox').checked = false; } }, 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);
diff --git a/docs/array.html b/docs/array.html
index e7b1e855e..bf6da70d6 100644
--- a/docs/array.html
+++ b/docs/array.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Array
all
Returns true if the provided predicate function returns true for all elements in a collection, false otherwise.
Use Array.every() to test if all elements in the collection return true based on fn. Omit the second argument, fn, to use Boolean as a default.
const all = (arr, fn = Boolean) => arr.every(fn);
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Array
all
Returns true if the provided predicate function returns true for all elements in a collection, false otherwise.
Use Array.every() to test if all elements in the collection return true based on fn. Omit the second argument, fn, to use Boolean as a default.
const all = (arr, fn = Boolean) => arr.every(fn);
 
all([4, 2, 3], x => x > 1); // true
 all([1, 2, 3]); // true
 
allEqual
Check if all elements are equal
Use Array.every() to check if all the elements of the array are the same as the first one.
const allEqual = arr => arr.every(val => val === arr[0]);
@@ -461,12 +461,13 @@
     .map(({ item }) => item);
 
const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
 const stable = stableSort(arr, () => 0); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-
symmetricDifference
Returns the symmetric difference between two arrays.
Create a Set from each array, then use Array.filter() on each of them to only keep values not contained in the other.
const symmetricDifference = (a, b) => {
+
symmetricDifference
Returns the symmetric difference between two arrays, without filtering out duplicate values.
Create a Set from each array, then use Array.filter() on each of them to only keep values not contained in the other.
const symmetricDifference = (a, b) => {
   const sA = new Set(a),
     sB = new Set(b);
   return [...a.filter(x => !sB.has(x)), ...b.filter(x => !sA.has(x))];
 };
-
symmetricDifference([1, 2, 3], [1, 2, 4]); // [3,4]
+
symmetricDifference([1, 2, 3], [1, 2, 4]); // [3, 4]
+symmetricDifference([1, 2, 2], [1, 3, 1]); // [2, 2, 3]
 
symmetricDifferenceBy
Returns the symmetric difference between two arrays, after applying the provided function to each array element of both.
Create a Set by applying fn to each array's elements, then use Array.filter() on each of them to only keep values not contained in the other.
const symmetricDifferenceBy = (a, b, fn) => {
   const sA = new Set(a.map(v => fn(v))),
     sB = new Set(b.map(v => fn(v)));
@@ -563,6 +564,11 @@ managers; //
   ],
   (a, b) => a.id == b.id
 ); // [ { id: 0, value: 'e' }, { id: 1, value: 'd' }, { id: 2, value: 'c' } ]
+
uniqueSymmetricDifference
Returns the unique symmetric difference between two arrays, not containing duplicate values from either array.
Use Array.filter() and Array.includes() on each array to remove values contained in the other, then create a Set from the results, removing duplicate values.
const uniqueSymmetricDifference = (a, b) => [
+  ...new Set([...a.filter(v => !b.includes(v)), ...b.filter(v => !a.includes(v))])
+];
+
uniqueSymmetricDifference([1, 2, 3], [1, 2, 4]); // [3, 4]
+uniqueSymmetricDifference([1, 2, 2], [1, 3, 1]); // [2, 3]
 
unzip
Creates an array of arrays, ungrouping the elements in an array produced by zip.
Use Math.max.apply() to get the longest subarray in the array, Array.map() to make each element an array. Use Array.reduce() and Array.forEach() to map grouped values to individual arrays.
const unzip = arr =>
   arr.reduce(
     (acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),
diff --git a/docs/browser.html b/docs/browser.html
index cf55e18f7..fafa46fb4 100644
--- a/docs/browser.html
+++ b/docs/browser.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Browser
arrayToHtmlList
Converts the given array elements into <li> tags and appends them to the list of the given id.
Use Array.map(), document.querySelector(), and an anonymous inner closure to create a list of html tags.
const arrayToHtmlList = (arr, listID) =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Browser
arrayToHtmlList
Converts the given array elements into <li> tags and appends them to the list of the given id.
Use Array.map(), document.querySelector(), and an anonymous inner closure to create a list of html tags.
const arrayToHtmlList = (arr, listID) =>
   (el => (
     (el = document.querySelector('#' + listID)),
     (el.innerHTML += arr.map(item => `<li>${item}</li>`).join(''))
diff --git a/docs/date.html b/docs/date.html
index 8bfdf5825..e67253e3c 100644
--- a/docs/date.html
+++ b/docs/date.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Date
formatDuration
Returns the human readable format of the given number of milliseconds.
Divide ms with the appropriate values to obtain the appropriate values for day, hour, minute, second and millisecond. Use Object.entries() with Array.filter() to keep only non-zero values. Use Array.map() to create the string for each value, pluralizing appropriately. Use String.join(', ') to combine the values into a string.
const formatDuration = ms => {
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Date
formatDuration
Returns the human readable format of the given number of milliseconds.
Divide ms with the appropriate values to obtain the appropriate values for day, hour, minute, second and millisecond. Use Object.entries() with Array.filter() to keep only non-zero values. Use Array.map() to create the string for each value, pluralizing appropriately. Use String.join(', ') to combine the values into a string.
const formatDuration = ms => {
   if (ms < 0) ms = -ms;
   const time = {
     day: Math.floor(ms / 86400000),
diff --git a/docs/function.html b/docs/function.html
index 76e32be6f..8a7eb96d6 100644
--- a/docs/function.html
+++ b/docs/function.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Function
attempt
Attempts to invoke a function with the provided arguments, returning either the result or the caught error object.
Use a try... catch block to return either the result of the function or an appropriate error.
const attempt = (fn, ...args) => {
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Function
attempt
Attempts to invoke a function with the provided arguments, returning either the result or the caught error object.
Use a try... catch block to return either the result of the function or an appropriate error.
const attempt = (fn, ...args) => {
   try {
     return fn(...args);
   } catch (e) {
diff --git a/docs/math.html b/docs/math.html
index 6943efdb1..1ae74e222 100644
--- a/docs/math.html
+++ b/docs/math.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Math
approximatelyEqual
Checks if two numbers are approximately equal to each other.
Use Math.abs() to compare the absolute difference of the two values to epsilon. Omit the third parameter, epsilon, to use a default value of 0.001.
const approximatelyEqual = (v1, v2, epsilon = 0.001) => Math.abs(v1 - v2) < epsilon;
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Math
approximatelyEqual
Checks if two numbers are approximately equal to each other.
Use Math.abs() to compare the absolute difference of the two values to epsilon. Omit the third parameter, epsilon, to use a default value of 0.001.
const approximatelyEqual = (v1, v2, epsilon = 0.001) => Math.abs(v1 - v2) < epsilon;
 
approximatelyEqual(Math.PI / 2.0, 1.5708); // true
 
average
Returns the average of two or more numbers.
Use Array.reduce() to add each value to an accumulator, initialized with a value of 0, divide by the length of the array.
const average = (...nums) => nums.reduce((acc, val) => acc + val, 0) / nums.length;
 
average(...[1, 2, 3]); // 2
diff --git a/docs/node.html b/docs/node.html
index 6a8af36e3..8de9947c3 100644
--- a/docs/node.html
+++ b/docs/node.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Node
atob
Decodes a string of data which has been encoded using base-64 encoding.
Create a Buffer for the given string with base-64 encoding and use Buffer.toString('binary') to return the decoded string.
const atob = str => new Buffer(str, 'base64').toString('binary');
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Node
atob
Decodes a string of data which has been encoded using base-64 encoding.
Create a Buffer for the given string with base-64 encoding and use Buffer.toString('binary') to return the decoded string.
const atob = str => new Buffer(str, 'base64').toString('binary');
 
atob('Zm9vYmFy'); // 'foobar'
 
btoa
Creates a base-64 encoded ASCII string from a String object in which each character in the string is treated as a byte of binary data.
Create a Buffer for the given string with binary encoding and use Buffer.toString('base64') to return the encoded string.
const btoa = str => new Buffer(str, 'binary').toString('base64');
 
btoa('foobar'); // 'Zm9vYmFy'
diff --git a/docs/object.html b/docs/object.html
index 51e683acf..7c8cc0752 100644
--- a/docs/object.html
+++ b/docs/object.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Object
bindAll
Binds methods of an object to the object itself, overwriting the existing method.
Use Array.forEach() to return a function that uses Function.apply() to apply the given context (obj) to fn for each function specified.
const bindAll = (obj, ...fns) =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Object
bindAll
Binds methods of an object to the object itself, overwriting the existing method.
Use Array.forEach() to return a function that uses Function.apply() to apply the given context (obj) to fn for each function specified.
const bindAll = (obj, ...fns) =>
   fns.forEach(
     fn => (
       (f = obj[fn]),
diff --git a/docs/string.html b/docs/string.html
index 527056f83..dce1a4a05 100644
--- a/docs/string.html
+++ b/docs/string.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
String
byteSize
Returns the length of a string in bytes.
Convert a given string to a Blob Object and find its size.
const byteSize = str => new Blob([str]).size;
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
String
byteSize
Returns the length of a string in bytes.
Convert a given string to a Blob Object and find its size.
const byteSize = str => new Blob([str]).size;
 
byteSize('😀'); // 4
 byteSize('Hello World'); // 11
 
capitalize
Capitalizes the first letter of a string.
Use array destructuring and String.toUpperCase() to capitalize first letter, ...rest to get array of characters after first letter and then Array.join('') to make it a string again. Omit the lowerRest parameter to keep the rest of the string intact, or set it to true to convert to lowercase.
const capitalize = ([first, ...rest], lowerRest = false) =>
diff --git a/docs/type.html b/docs/type.html
index 958ae2533..b1d1377cd 100644
--- a/docs/type.html
+++ b/docs/type.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Type
getType
Returns the native type of a value.
Returns lowercased constructor name of value, "undefined" or "null" if value is undefined or null.
const getType = v =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Type
getType
Returns the native type of a value.
Returns lowercased constructor name of value, "undefined" or "null" if value is undefined or null.
const getType = v =>
   v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
 
getType(new Set([1, 2, 3])); // 'set'
 
is
Checks if the provided value is of the specified type.
Ensure the value is not undefined or null using Array.includes(), and compare the constructor property on the value with type to check if the provided value is of the specified type.
const is = (type, val) => ![, null].includes(val) && val.constructor === type;
diff --git a/docs/utility.html b/docs/utility.html
index fe1623b59..764bc43ea 100644
--- a/docs/utility.html
+++ b/docs/utility.html
@@ -79,7 +79,7 @@
             document.getElementById('doc-drawer-checkbox').checked = false;
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Utility
castArray
Casts the provided value as an array if it's not one.
Use Array.isArray() to determine if val is an array and return it as-is or encapsulated in an array accordingly.
const castArray = val => (Array.isArray(val) ? val : [val]);
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Utility
castArray
Casts the provided value as an array if it's not one.
Use Array.isArray() to determine if val is an array and return it as-is or encapsulated in an array accordingly.
const castArray = val => (Array.isArray(val) ? val : [val]);
 
castArray('foo'); // ['foo']
 castArray([1]); // [1]
 
cloneRegExp
Clones a regular expression.
Use new RegExp(), RegExp.source and RegExp.flags to clone the given regular expression.
const cloneRegExp = regExp => new RegExp(regExp.source, regExp.flags);