const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] const evenNumbers = numbers.filter((num) => num % 2 === 0) console.log(evenNumbers) // [2, 4, 6, 8, 10]
const words = ['apple', 'banana', 'cherry', 'date', 'elderberry'] const fiveLetterWords = words.filter((word) => word.length === 5) console.log(fiveLetterWords) // ['apple', 'cherry', 'date']
array.filter(callback(element[, index[, array]])[, thisArg])
Array.prototype.filter() method is a higher-order function that allows you to create a new array with all elements that pass a test implemented by a provided function. It is a useful method for filtering out unwanted elements from an array and creating a new array with only the desired elements.
filter() method takes a callback function as its first argument.
This callback function is called for each element in the array, and it should return a boolean value indicating whether the element should be included in the new filtered array. If the callback function returns true for a given element, that element will be included in the new array.
If it returns false, the element will be excluded.
The callback function can take up to three arguments:
element: the current element being processed in the array
index(optional): the index of the current element in the array
array(optional): the array the
filter()method was called on
filter() method also takes an optional second argument, which is used as the this value inside the callback function.
filter()method is part of the Array.prototype, which means it is available to be used on any array object.
filter()method does not modify the original array, but rather creates a new array with the elements that pass the test implemented by the callback function.
filter()method is a useful way to select a subset of elements from an array based on a certain criterion.
filter() method is supported in all modern browsers, including Internet Explorer 9 and above.
Array.prototype.map(): creates a new array with the results of calling a provided function on every element in the original array
Array.prototype.find(): returns the value of the first element in the array that satisfies the provided testing function
Array.prototype.some(): tests whether at least one element in the array passes the test implemented by the provided function