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This article introduces which of the 10 JavaScript code segments you can use now, the content is very detailed, interested friends can refer to it, I hope it can be helpful to you.

Without a doubt, JavaScript is one of the most popular programming languages in Web development. Whether you are using React,Vue or Angular, it is just JavaScript. There is an extensive and important ecosystem around JS, providing countless frameworks and libraries to help you develop applications faster.

But sometimes it's best to take a step back and try to understand how to do things without a library. Take a look at the code snippet below to solve simple problems in an elegant way and use this knowledge in daily project situations or prepare for a coded interview.

1. Reverse string

In this example, we use the extension operator (...) The reverse method of Array and the join method of String to reverse the given string.

Const reverseString = string = > [... string] .reverse () .join (''); / / example reverseString ('javascript'); / /' tpircsavaj' reverseString ('good'); / /' doog'

two。 Calculate the factorial of a number

To calculate the factorial of a given number, we use the arrow function and the nested ternary operator.

Const factoriaOfNumber = number = > number

{throw new TypeError ('No negative numbers please');}) (): number [. `${number}`] .map (el = > parseInt (el)); / / example convertToArray (5678); / / [5,6,7,8] convertToArray (123456789); / / [1, 2, 3, 4, 5, 6, 7, 8, 9]

4. Check whether the number is a power of 2

There's nothing to it. We check that the number is not forged and use the bitwise AND operator (&) to determine whether the number is a power of 2.

Const isNumberPowerOfTwo = number = >! number & & (number & (number-1)) = = 0; / / example isNumberPowerOfTwo; / / false isNumberPowerOfTwo (128); / / true

5. Create an array of key-value pairs from an object

In this example, we use the keys method in Object and the map method in Array to map the keys of Object and create a key / value pair array.

Const keyValuePairsToArray = object = > Object.keys (object) .map (el = > [el, object [el]]); / / example keyValuePairsToArray ({Better: 4, Programming: 2}); / / [['Better', 4], [' Programming', 2]] keyValuePairsToArray ({x: 1, y: 2, z: 3}); / / [['x, 1], [yearly, 2], ['zonal, 3]]

6. Returns the [Number] largest element in the array

To return the largest element from the array, we use an arrow function that gets the array and the number of elements we want the function to return. We use the extension operator (...) And the sort and slice methods in Array. Note that if we do not provide the second parameter, the default value of number is 1, so only one maximum element is returned.

Const maxElementsFromArray = (array, number = 1) = > [... array] .sort ((x, y) = > y-x) .slice (0, number); / / example maxElementsFromArray ([1, number, 3)); / / [5] maxElementsFromArray ([7, 8), 9, 10, 10]; / / [10, 10]

7. Check that all elements in the array are equal

In this short example, we use the every method in Array to check that all elements in the array are equal. We basically check whether each element is equal to the first element in the array.

Const elementsAreEqual = array = > array.every (el = > el = = array [0]); / / example elementsAreEqual ([9, 8, 7, 6, 5]); / / false elementsAreEqual ([4, 4, 4, 4, 4, 4, 4, 5]); / / true

8. Returns the average of two numbers

In this example, we use the extension operator (...) And the reduce method in Array to return the average of two given numbers or an array.

Const averageOfTwoNumbers = (... numbers) = > numbers.reduce ((accumulator, currentValue) = > accumulator + currentValue, 0) / numbers.length; / / example averageOfTwoNumbers (.

9. Returns the sum of two or more numbers

To return the sum of two or more given numbers or an array, we use the extension operator again (…) And the reduce method in Array.

Const sumOfNumbers = (... array) = > [... array]. Reduce ((accumulator, currentValue) = > accumulator + currentValue, 0); / / example sumOfNumbers (5 sumOfNumbers, 6, 7, 8, 9, 10); / / 45 sumOfNumbers (.

10. Returns the power set of an array of numbers

In the last example, we want to return the power set of an array of numbers. Therefore, we use the reduce,map and concat methods in Array.

Const powersetOfArray = array = > array.reduce ((accumulator, currentValue) = > accumulator.concat (accumulator.map (el = > [currentValue] .concat (el)), [[]]); / / example powersetOfArray ([4,2]); / / [[], [4], [2], [2,4]] powersetOfArray ([1,2,3]) / [[], [1], [2], [2, 1], [3], [3, 1], [3, 2], [3, 2, 1]]

As you can see, using JavaScript and some ES6 magic to solve these tasks is not always difficult.

This is the end of the 10 JavaScript code snippets that you can use now. I hope the above content can be of some help and learn more knowledge. If you think the article is good, you can share it for more people to see.

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