Array is JS The most common data structure , We often use it in development , In this article , Here are some tips , Help us improve development efficiency .
1. Remove duplicate items from array
2. Replace a specific value in an array
Sometimes you need to replace a specific value in an array when you create code , There is a good short way to do this , We can use it .splice(start,value to
remove,valueToAdd), These parameters specify where we want to start , How many values are modified and replaced with new values .
3. Array.from achieve .map The effect of
We all know that .map() method ,.from() Methods can also be used to achieve similar results, and the code is concise .
4. Empty array
Sometimes we need to empty the array , A quick way is to directly let the array length Property is 0, You can empty the array .
5. Convert array to object
occasionally , For some purpose , You need to convert the array to an object , A simple and fast way is to use the expansion operation symbol (...):
6. Fill the array with data
In some cases , When we create an array and want to fill it with some data , At this time .fill() Methods can help us .
7. Array merging
Using the expand operator , You can also combine multiple arrays .
8. Find the intersection of two arrays
Finding the intersection of two arrays is also a difficult point in the interview , To find the intersection of two arrays , First, use the above method to ensure that the values in the checked array are not repeated , Then use .filter Methods and
.includes method . As shown below ：
9. Remove virtual values from array
stay JS in , Virtual value has false, 0,'', null, NaN, undefined. We can .filter() Method to filter these virtual values .
10. Get random values from an array
Sometimes we need to select an array of random values . A convenient way is to get a random index according to the length of the array , As shown below ：
11. Invert array
Now? , When we need to reverse the array , There is no need to create it through complex loops and functions , Array of reverse The method can be done ：
12 lastIndexOf() method
13. Sums all values in an array
JS It's often used in interviews reduce Methods to solve problems skillfully
summary
In this paper , Introduced 13 Tips , Hopefully, they can help write concise code , If you have a better way , Welcome to leave a message for discussion .
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