JavaScript Array Playground
Array.filter()Pure
Creates a new array with all elements that pass the test implemented by the provided function. More
Array.find()Pure
Returns the value of the first element in the array that satisfies the provided testing function. Otherwise undefined is returned. More
Array.findIndex()Pure
Returns the index of the first element in the array that satisfies the provided testing function. Otherwise -1 is returned. More
Array.map()Pure
Creates a new array with the results of calling a provided function on every element in the calling array. More
Array.reduce()Pure
Applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value. More
Array.filter().map()
Two method can put together.
Array.sort()Impure
Sorts the elements of an array and returns the array. We can define the conditions for sorting. More
Array.reverse()Impure
Reverses an array in place. More
Array.push()Impure
Adds one or more elements to the end of an array and returns the new length of the array. More
PushPure
We can pure push too.
Array.shift()Impure
Removes the first element from an array and returns that removed element. This method changes the length of the array. More
Array.pop()Impure
Removes the last element from an array and returns that element. This method changes the length of the array. More
Array.splice()Impure
Changes the contents of an array by removing existing elements and/or adding new elements. More
Array.join()Pure
Joins all elements of an array (or an array-like object) into a string and returns this string. More
Array.concat()Pure
This method is used to merge two or more arrays. This method does not change the existing arrays, but instead returns a new array. More
Array.slice()Pure
Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included). The original array will not be modified. More
Array.toString()Pure
Returns a string representing the specified array and its elements. More
Copy ArrayPure
pure Copy Array
Array.copyWithin()Impure
Shallow copies part of an array to another location in the same array and returns it, without modifying its size. More
Array.entries()Pure
Returns a new Array Iterator object that contains the key/value pairs for each index in the array. More
Array.every()Pure
Tests whether all elements in the array pass the test implemented by the provided function. More
Array.fill()Impure
Fills all the elements of an array from a start index to an end index with a static value. The end index is not included. More
Array.find()Pure
Returns the value of the first element in the array that satisfies the provided testing function. Otherwise undefined is returned. More
Array.forEach()Pure
Executes a provided function once for each array element. More
Array.includes()Pure
Determines whether an array includes a certain element, returning true or false as appropriate. It uses the sameValueZero algorithm to determine whether the given element is found. More
Array.from()Pure
Creates a new, shallow-copied Array instance from an array-like or iterable object. More
Array.of()Pure
Creates a new Array instance with a variable number of arguments, regardless of number or type of the arguments. More
Array.indexOf()Pure
Returns the first index at which a given element can be found in the array, or -1 if it is not present. More
Array.keys()Pure
Returns a new Array Iterator object that contains the keys for each index in the array. More
Array.lastIndexOf()Pure
Returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex. More
Array.map()Pure
Creates a new array with the results of calling a provided function on every element in the calling array. More
Array.reduceRight()Impure
Applies a function against an accumulator and each value of the array (from right-to-left) to reduce it to a single value. More
Array.some()Pure
Tests whether at least one element in the array passes the test implemented by the provided function. More
Array.toLocaleString()Pure
Returns a string representing the elements of the array. The elements are converted to Strings using their toLocaleString methods and these Strings are separated by a locale-specific String (such as a comma “,”). More
Array.unshift()Impure
Adds one or more elements to the beginning of an array and returns the new length of the array. More
Array.values()Pure
Returns a new Array Iterator object that contains the values for each index in the array. More
Array[Symbol.iterator]()Pure
Property is the same function object as the initial value of the values() property. More
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