Every ES6 Array method you must know to be a JavaScript Expert

We go through the 30 most important new and existing ES6 methods you need to be a true JavaScript expert.

Creating & Merging
concat(): Merge two or more arrays, and returns a new array
fill(): Fill the elements in an array with a static value
from(): Creates an array from an object

Foreach vs Map
forEach(): Calls a function once for each array element
map(): Creates a new array with the results of calling a function for each array element

Testing & Filtering
filter(): Creates a new array with all elements that pass the test in a testing function
every(): Checks if every element in an array passes a test in a testing function
isArray(): Determines whether the passed value is an array
some(): Checks if any of the elements in an array passes the test in a testing function

Reducers
reduce(): Reduce the values of an array to a single value (from left-to-right)
reduceRight(): Reduce the values of an array to a single value (from right-to-left)

Search & Find
find(): Returns the value of the first element in an array that pass the test in a testing function
findIndex(): Returns the index of the first element in an array that pass the test in a testing function
includes(): Determines whether an array includes a certain element
indexOf(): Search the array for an element and returns its first index
lastIndexOf(): Search the array for an element, starting at the end, and returns its last index

Pushing & Popping
pop(): Removes the last element from an array, and returns that element
push(): Adds one or more elements to the end of an array, and returns the array's new length
shift(): Removes the first element from an array, and returns that element
unshift(): Adds new elements to the beginning of an array, and returns the array's new length

Slice vs Splice
slice(): Selects a part of an array, and returns the new array
splice(): Adds/Removes elements from an array

Sorting
sort(): Sorts the elements of an array
copyWithin(): Copies part of an array to another location in the same array and returns it
reverse(): Reverses the order of the elements in an array

Display
join(): Joins all elements of an array into a string
toString(): Converts an array to a string, and returns the result

Iterators
entries(): Returns a key/value pair Array Iteration Object
keys(): Returns an Array Iteration Object, containing the keys of the original array
values(): Returns an Array Iteration Object, containing the values of the original array

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[ajimahifeanyi]

Thanks for this. Really helpful. Love from Nigeria.

[JayWolters]

What plugin are you using to show the objects and arrays when you type the name?