My personal collection of utility functions.

General purpose utility functions.

Interprets whether a string means yes or not.

• str string Test string.

yes('yes'); // true

yes('yup'); // true

yes('no'); // false

Returns boolean No?

Interprets whether a string means no or not.

• str string Test string.

no('no'); // true

no('nope'); // true

no('yes'); // false

Returns boolean Yes?

Checks whether two dates are within N days of each other.

• date1 Date First date.
• date2 Date Second date.
• days number Number of days. (optional, default 1)

Returns boolean Whether the two dates are within N days of each other.

Prints a date as a string in YYYY/mm/dd format.

• date Date Date to print.
• separator string Separator used between dates. (optional, default '/')

Returns string String of date.

Prints a date for a CSV file in YYYY/mm/dd format.

• date Date Date to print.

Returns string String of date to be inserted into a CSV cell.

Omits keys with values that are empty from object.

• obj Object<string, any> Object to omit values from.

Returns Object<string, any> Object with null, undefined, or empty string values omitted.

Gets unique values from array.

• arr Array<T> Array of items.
• filter (string | function (T, number, Array<T>): (number | string))? String or function to filter by.

Returns Array Array with unique values.

Meta

• since: 1.0.5 - The filter parameter was added.

Type: Object<(string | number), boolean>

Gets difference between two arrays.

• arr1 Array<any> First array.
• arr2 Array<any> Second array.

Returns Array<any> Array with values removed.

Partitions array based on conditions.

• arr Array<T> Array.
• method function (T): boolean Function to satisfy.

Returns [Array<T>, Array<T>] Partitioned array.

Type: [Array<T>, Array<T>]

Averages an array of numbers.

• numbers Array<number> Array of numbers.

Returns number Average of all numbers in array.

Averages an array of numbers.

• numbers Array<number> Array of numbers.

Returns number Average of all numbers in array.

Meta

• deprecated: Since version 1.1.4 - Use average instead.

Gets the mean of an array of numbers.

• numbers Array<number> Array of numbers.

Returns number Average of all numbers in array.

Gets the median from an array of numbers.

• numbers Array<number> Array of numbers.

Returns (number | undefined) Median of numbers, or undefined if array is empty.

Gets mode from array of numbers.

• numbers Array<number> Array of numbers.

Returns (number | undefined) Mode of numbers, or undefined if array is empty.

Groups an array by value from key.

• arr Array<T> Array.
• key (string | function (T): (number | string)) Key to take value from.

Returns Object<string, Array<T>> Object of groups.

Indexes an array by value from key.

• arr Array<T> Array.
• key (string | function (T): (string | number)) Key to take value from.

Returns Object<string, T> Indexed object.

Flattens an array.

• arr Array<(Array<any> | any)> Array to flatten.

Returns Array<any> Flattened array.

Type: Array<(Array<any> | any)>

Flattens an array (shallow).

• arr Array<(Array<any> | any)> Array to flatten.

Returns Array<(Array<any> | any)> Flattened array.

Type: Array<(Array<any> | any)>

Removes all falsy values from an array.

• arr Array<any> Array to compact.

Returns Array<any> Compacted array.

Flattens and compacts array.

• arr Array<(Array<any> | any)> Array to flatten.
• deep boolean? Whether to deeply flatten array.

Returns Array<(Array<any> | any)> Flattened and compacted array.

Meta

• deprecated: Since version 1.1.4 - Use flatten and compact separately.

Creates a range of numbers from start to stop, non-inclusive.

• start number Number to start at.
• end number Number to end at.

range(1, 3); // [1, 2]

Returns Array Array of numbers in range.

Create a random string.

• length Number Length of string. (optional, default 10)

Returns String Random string.

Picks keys from an object.

• obj Object Object to pick values from.
• keys ...(string | Array<string>) Keys to pick. Keys can also be contained within an array.

Returns Object Object with picked keys.

Creates a tree within an object.

Modifies the original object.

• obj Object Object to build tree on.
• tree Array Tree to build on 'obj'.
• tail any? Any value to use as the tail.

createTree({}, ['fruit', 'color'], 'red'); // { fruit: { color: 'red' } }

Returns Object The same object passed as 'obj'.

Recursively transforms key/values in object, including array values.

Also can act as a basic deep clone method.

• obj Object Object to transform.
• transforms Object Object containing transformation functions.
  • transforms.keys function (string, number): any? Function for transforming keys from 'obj'.
  • transforms.values function (any, number): any? Function for transforming values from 'obj'.
• level number Level of recursion, passed as the 2nd argument to a transform function. (optional, default 0)

transformObj({
    apple: 'Green',
    orange: 'Orange',
    cherry: {
        color: 'Red'
    }
}, {
    keys: (key, level) => {
        return level === 0 ? `fruit_${key}` : key;
    },
    values: (value) => {
        return value.toUpperCase();
    }
});
// { fruit_apple: 'GREEN', fruit_orange: 'ORANGE', fruit_cherry: { color: 'RED' } }

Returns Object Transformed object.

Recursively clones an object's values.

This works for simple objects containing simple types like strings, number, and dates. Complex objects containing state may have issues.

• obj Object Object.

Returns Object Cloned object.

Meta

• since: 1.0.7 - method clones more than just primitive values

Type: object

Creates an object from an array of keys.

• keys (Array<string> | Array<number>) Array of keys.
• value any? Value to assign to each key.

arrToKeys(['a', 'b'], 0);
// { a: 0, b: 0 }

Returns Object<(string | number), any> Object with keys mapped from array.

Checks if a value is a number or not.

• value any Value to test.

Returns boolean Whether the value is a number or not.

Truncates a string with option to add trail at end.

• str string String.
• length number Length to trim to.
• trail string Trailing characters. (optional, default '')

Returns string Truncated string.

Chooses a form based on number.

• singular string Singular form.
• plural string Plural form.
• value number Test value.

Returns string Form based on value.

Chooses a form based on number.

• singular string Singular form.
• plural string Plural form.
• value number Test value.

Returns string Form based on value.

Meta

• deprecated: Since version 1.1.4 - Use pluralize instead.

Assigns values of object as keys.

• obj Object Object.

valuesAsKeys({ a: 'apple' });
// { a: 'apple', 'apple': 'a' }

Returns Object Object with values mapped as keys.

Escapes a cell value in CSV.

• str string String.

Returns string Escaped string.

Escapes a string in RegExp.

• str string String.

Returns string Escaped string.

Escapes text to use as strings in HTML format.

• text string Text to escape.

Returns string Escaped text.

Picks a number of items from an array at random.

• arr Array<any> Array to pick items from.
• num number Number of items to take.

takeNRandom([1, 2, 3, 4, 5], 3);
// [3, 5, 2]

Returns Array<any> N number of values taken from array at random.

Picks a number of items from an array at random.

Faster when picking a lower amount of numbers from array.

• arr Array<any> Array to pick items from.
• num number Number of items to take.

Returns Array<any> N number of values taken from array at random.

Picks a number of items from an array at random.

Faster when picking a larger amount of numbers from array.

• arr Array<any> Array to pick items from.
• num number Number of items to take.

Returns Array<any> N number of values taken from array at random.

Executes a series of Promises in a series, where each Promise resolves before the next function is called.

• funcs Array<(function (): Promise<any>)> An array of functions where each function returns a Promise.

const urls = ['/url1', '/url2', '/url3'];
promiseSeries(urls.map(url => () => $.ajax(url)))
    .then(response => console.log(response));

Returns Promise<Array<any>> Promise that resolves with an array containing results from each resolved Promise in series.

Concatenates an array to a list.

• list Array<any> List to concatenate.

Returns function (Array<any>): Array<any> Concatenated list.

Concatenates resolves from previous functions with resolves from current function.

• func function (): Promise<any> Function that returns a Promise.

Returns function (Array<any>): Promise<any> Function that returns a Promise.

Reduces an array of functions that return Promises in series.

• accum Promise<any> Accumulator Promise, this will add a value to the accumulator for each function in the series.
• func function (): Promise<any> Function that returns a Promise.

Returns Promise<Array<any>> Promise that resolves with the result of the last function in the series.

Delays a promise.

• time number Time in ms to delay.
• value any? Value to pass to resolve.

Returns Promise Promise that resolves after the given delay.

Meta

• since: 1.0.1 - The time parameter comes first.

Sleeps for a set amount of time.

• time number? Time in ms to delay.

Returns Promise Promise that resolves after the given delay.

Checks if A is equal to B.

• a T Value A.
• b T Value B.

Returns boolean Whether A is equal to B.

Gets a list of property names of an object.

• obj Object<string, any> Object to get properties from.

Returns Array<string> Property names of object.

Checks if all values are the same in both objects.

• a Object<string, any> Object A.
• b Object<string, any> Object B.
• props Array<any> Properties to check.

Returns boolean Whether all values are the same in both objects.

Checks if a value is an object.

• value any Value to check.

Returns boolean Whether the value is an object.

Removes elements from an object or array by value.

• item (Object | Array<any>) Item to process.
• value (any | Array<any>) Value or array of values to remove from item.

without({ name: 'cat', color: 'orange' }, ['orange']); // { name: 'cat' }

without(['cat', 'orange'], ['orange']); // ['cat']

// or using just a string
without(['cat', 'orange'], 'orange'); // ['cat']

Returns (Object | Array<any>) Object or array without the given values.

Checks if an element does not match the value.

• element any Element to check.

Returns boolean Whether the element does not match the value.

Checks if an item does not have a key.

• key string Key to check.

Returns boolean Whether the item does not have the key.

Takes values to remove from 'item' and adds them to a new object.

• newItem Object New object to add values to.
• key string Key to add to new object.

Returns Object New object with values added.

Shortens a sentence-like string without cutting off the final word.

• str string String to shorten.
• maxLength number Max length of string.
• seperator (string | RegExp) Word seperator. If a RegExp is given, words will be seperated by a space. (optional, default ' ')

shorten('that cat is fat', 8); // 'that cat'

// custom seperator
shorten('123x456x789', 8, 'x'); // '123x456'

Returns string Shortened string.

Rounds number to N decimal places.

• value number Value to round.
• places number Places to round to.

roundN(4.344, 1); // 4.3

Returns number Rounded number.

Gets the closest value to a given number in the array.

• arr Array<T> Array of anything. If comparing non-numbers, a key should be given.
• num number Number to be closest to.
• key (string | function (T, number): number)? Key or method to extract value from each item.

// gets the closest value in array to 6
closest([1, 5, 9], 6); // 5

// gets the city with the closest population to 11e5
const cities = [
    {
        name: 'New York',
        population: 86e5
    },
    {
        name: 'Tokyo',
        population: 138e5
    },
    {
        name: 'Mumbai',
        population: 124e5
    }
];

closest(cities, 11e5, 'population'); // { name: 'Mumbai', population: 12.4 }

Returns (T | undefined) Closest value in array.

Type: T

Type: number

Sorts an array in a chain.

• arr Array<T> Array to sort.
• funcs Array<(function (T, T): number)> Array of functions.

chainSort([1, 5, 9, 4, 2], [
    (a, b) => {
        return a - b;
    }
]);
// [1, 2, 4, 5, 9]

Returns Array<T> Sorted array.