Find vs for loop javascript
How to perform common operations in JavaScript where you might use loops, using map(), filter(), reduce() and find()Published Apr 13 2018, Last Updated Apr 16 2018 Show
Loops are generally used, in any programming language, to perform operations on arrays: given an array you can iterate over its elements and perform a calculation. Let’s see how to pick common needs and perform them using a Functional Programming approach, as opposed to using loops.
map, filter, reduce, findThose are 3 really powerful array functions:
They offer a more declarative approach, rather than an imperative approach (describe what should happen, not write every tiny bit of processing that should happen) Execute something on every element with mapA loop would look like this:
With a declarative approach, you tell JavaScript to perform something on every element using:
This generates a new array, without editing the original one (what we call immutability) Since we use a single function in the map callback function, we can rewrite the sample as:
Finding a single element in the arraySometimes you need to look for a specific item in the array, and return it. This is how you would do so with a loop:
Here is the non-loop version, using
Here is the same functionality using
Note: For learning purposes (does not make much sense in practice), here is the same functionality using
Iterate over an array to count a property of each itemUse
using a loop:
can written as
Is find better than for loop?find() is better due to complexity level and the internal algorithm used. Using for...break you will always doing a linear search which means n * n repetitions. The bigger the array, the slower the function.
What is faster than for loop in JavaScript?forEach loop
The forEach method in Javascript iterates over the elements of an array and calls the provided function for each element in order. The execution time of forEach is dramatically affected by what happens inside each iteration. It is fast and designed for functional code.
Is map () faster than for loop?map() works way faster than for loop. Considering the same code above when run in this ide.
Which loop is better in JavaScript?The fastest loop is a for loop, both with and without caching length delivering really similar performance.
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