JavaScript Arrays - Object

Method	Mutates	Description
concat	no
copyWithin	mutates
every
fill	mutates
filter		change size, not shape always returns an array the callback function must return True or False
find		change the shape to 1 returns the value of the first element that satisfies the provided testing function. does not return an array, returns the first instance, otherwise undefined
findIndex
forEach
from
includes
indexOf
join
lastIndexOf
length
map		change shape, not size, takes a callback function that takes one argument and applies the fn to each argument it will take each item and add it to an array always returns an array useful when you have an array of objects
pop	mutates	removes and displays the last item from the end
push	mutates	adds an item to the end
reduce		changes the shape and changes the size may or may not return an array executes a reducer function (that you provide) on each element of the array, resulting in single output value.
reduceRight
reverse	mutates	reverse the order of the items
shift	mutates	remove an item from the beginning of an array
slice		remove and displays part of the array
some
sort	mutates	alphabetically sort items.
splice	mutates	modifies an array by removing existing elements and/or adding new elements.
split
unshift	mutates	adds an item to the beginning of an array, and returns the new length