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);
+ } 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less. Search for snippet...
Adapter call collectInto flip over pipeFunctions promisify spreadOver Array chunk compact countBy countOccurrences deepFlatten difference differenceBy differenceWith dropElements dropRight everyNth filterNonUnique findLast flatten forEachRight groupBy head indexOfAll initial initialize2DArray initializeArrayWithRange initializeArrayWithRangeRight initializeArrayWithValues intersection isSorted join last longestItem mapObject maxN minN nthElement partition pull pullAtIndex pullAtValue reducedFilter remove sample sampleSize shuffle similarity sortedIndex symmetricDifference symmetricDifferenceBy symmetricDifferenceWith tail take takeRight union unionBy unionWith uniqueElements unzip without zip zipObject zipWith Browser arrayToHtmlList bottomVisible copyToClipboard createElement createEventHub currentURL detectDeviceType elementIsVisibleInViewport getScrollPosition getStyle hasClass hashBrowser hide httpsRedirect observeMutations off on onUserInputChange redirect runAsync scrollToTop setStyle show toggleClass UUIDGeneratorBrowser Date formatDuration getDaysDiffBetweenDates tomorrow Function chainAsync compose composeRight curry defer functionName memoize negate once runPromisesInSeries sleep Math average averageBy clampNumber digitize distance elo factorial fibonacci gcd geometricProgression hammingDistance inRange isDivisible isEven isPrime lcm luhnCheck maxBy median minBy percentile powerset primes randomIntArrayInRange randomIntegerInRange randomNumberInRange round sdbm standardDeviation sum sumBy sumPower toSafeInteger Node atob btoa colorize hasFlags hashNode isTravisCI JSONToFile readFileLines untildify UUIDGeneratorNode Object deepClone defaults equals findKey findLastKey forOwn forOwnRight functions get invertKeyValues lowercaseKeys mapKeys mapValues matches matchesWith merge objectFromPairs objectToPairs omit omitBy orderBy pick pickBy shallowClone size transform truthCheckCollection String anagrams byteSize capitalize capitalizeEveryWord decapitalize escapeHTML escapeRegExp fromCamelCase isAbsoluteURL isLowerCase isUpperCase mask palindrome pluralize reverseString sortCharactersInString splitLines toCamelCase toKebabCase toSnakeCase truncateString unescapeHTML URLJoin words Type getType is isArrayLike isBoolean isEmpty isFunction isNil isNull isNumber isObject isObjectLike isPlainObject isPrimitive isPromiseLike isString isSymbol isUndefined isValidJSON Utility castArray cloneRegExp coalesce coalesceFactory extendHex getURLParameters hexToRGB httpGet httpPost nthArg parseCookie prettyBytes randomHexColorCode RGBToHex serializeCookie timeTaken toDecimalMark toOrdinalSuffix validateNumber yesNo Adapter 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);
Show examples Promise. resolve ([ 1 , 2 , 3 ])
. then ( call ( 'map' , x => 2 * x))
. then ( console. log);
@@ -371,6 +371,15 @@ Object. assig
Show examples unionWith ([ 1 , 1.2 , 1.5 , 3 , 0 ], [ 1.9 , 3 , 0 , 3.9 ], ( a, b) => Math. round ( a) === Math. round ( b));
📋 Copy to clipboard uniqueElements Returns all unique values of an array.
Use ES6 Set and the ...rest operator to discard all duplicated values.
const uniqueElements = arr => [ ... new Set ( arr)];
Show examples uniqueElements ([ 1 , 2 , 2 , 3 , 4 , 4 , 5 ]);
+📋 Copy to clipboard 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),
+ Array. from ({
+ length: Math. max ( ... arr. map ( x => x. length))
+ }). map ( x => [])
+ );
+Show examples unzip ([[ 'a' , 1 , true ], [ 'b' , 2 , false ]]);
+unzip ([[ 'a' , 1 , true ], [ 'b' , 2 ]]);
📋 Copy to clipboard without Filters out the elements of an array, that have one of the specified values.
Use Array.filter() to create an array excluding(using !Array.includes()) all given values.
(For a snippet that mutates the original array see pull
const without = ( arr, ... args) => arr. filter ( v => ! args. includes ( v));
Show examples without ([ 2 , 1 , 2 , 3 ], 1 , 2 );
📋 Copy to clipboard zip Creates an array of elements, grouped based on the position in the original arrays.
Use Math.max.apply() to get the longest array in the arguments. Creates an array with that length as return value and use Array.from() with a map-function to create an array of grouped elements. If lengths of the argument-arrays vary, undefined is used where no value could be found.
const zip = ( ... arrays) => {
diff --git a/snippets/unzip.md b/snippets/unzip.md
index 9c01f9285..96503871e 100644
--- a/snippets/unzip.md
+++ b/snippets/unzip.md
@@ -10,7 +10,7 @@ const unzip = arr =>
arr.reduce(
(acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),
Array.from({
- length: Math.max(...arr.map(x => x.length)),
+ length: Math.max(...arr.map(x => x.length))
}).map(x => [])
);
```
30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.