Returns a new array with all elements of 'other' removed from the original array

a([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
 .difference([1, 2, 3]) ==
 [4, 5, 6, 7, 8, 9, 10]

Returns a new array that contains only the elements that are in both the original array and the 'other' array

a([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
 .intersect([1, 2, 3]) ==
 [1, 2, 3]

Sorts an array of objects by a given field. The sort is done lexographically

a([{name: "Joe"}, {name: "Bob"}, {name: "Ann"}])
 .sortBy("name") ==
 [{name: "Ann"}, {name: "Bob"}, {name: "Joe"}]

Partitions the elements of an array into separate arrays based on a partition function.

a([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
 .partition(n => n % 3) ==
 {
     0: [3, 6, 9],
     1: [1, 4, 7, 10],
     2: [2, 5, 8]
 }

Returns the maximum element in the array

Funcional-style assignment: Takes the result of an expression and passes it to the given function, returning the function's result.

o(1 + 2).as(sum => sum * 3) == 9

Logs the current object to the console, then returns it so method chaining can continue. This allows the developer to see intermediate results in a chain of function calls without disturbing the chain.

Filters an object like an array, keeping key=>value associations

o({a: 1, b: 2, c: 3}).filter(num => num % 2 > 0) == {a: 1, c: 3}

Gets the keys of an object

Maps an object like an array, keeping key=>mapped value associations

o({a:1, b:2, c:3}).map(n => n * 2) == {a:2, b: 4, c:6}

Merges two objects. By default, objects are merged recursively and arrays are concatenated. This behavior can be altered by sending the appropriate flags. Other values in the original object are replaced by the corresponding values in the second object.

Reduces an object like an array. Both keys and values are available to the reducer

Maps a function onto the elements of an object and merges the results into a single new object. o(obj).mergeReduce(f) === o(obj).map(f).reduce((a, b) => a.merge(b), o({}))

A functional switch statement. The value of the switch statement will be the return value of whichever action is run.

const mode = "json";
o(mode).switch({
 html: () => "<h1>Hello World!</h1>",
 json: () => ({msg: "Hello World!}),
 default: () => "Invalid format"
}) == {msg: "Hello World!}

Returns a new object with the specified field deleted

Returns the values of the object as an array

Cancel the delayed function. Note that the DelayedEvent can be re-queued by calling runIn() again.

Synonym for runIn, useful in fluent expressions

f(func).delay().for(5).seconds();

Set (or reset) the delay of the function

f(func).delay().for(5).seconds();

Interpret the previously specified delay as a delay in milliseconds

f(func).delay().for(5).milliseconds();

Interpret the previously specified delay as a delay in seconds

f(func).delay().for(5).seconds();

Interpret the previously specified delay as a delay in minutes

f(func).delay().for(5).minutes();

Interpret the previously specified delay as a delay in hours

f(func).delay().for(5).hours();

Interpret the previously specified delay as a delay in days

f(func).delay().for(5).days();