JavaScript Enhanced Tutorial - Basic Array Processing Functions

This article is the official HTML5 training tutorial of H5EDU organization. It mainly introduces: JavaScript intensive tutorial - basic processing function of array

Array.push(); adds elements at the end of the array and returns the new length of the array

Array.pop() ;Delete the last element, reduce the length of the array, and return the last element

Array.unshift();Add elements in front of the array

Array.splice(n,x); //n array subscript x delete several Start deleting from n
(when x=1, it means deleting the element whose current index is n)

indexOf() searches the entire array for elements with a given value and returns the index of the first element found or if not found Returns -1

map() method passes each element of the called array to the specified function and returns an array containing the return value of the function
a= [1,2,3];
b=a. map(function(){ return x*x;}); //b is [1,4,9]

The basic processing function of character array

1.substr(x,n) outputs a string from x Output n characters backwards
Tips are similar to splice(x,n); substr(n) from nth to last
2.charAt(n) outputs the nth character in the string
3.charCodeAt(n) Output the nth character encoding
For example, check the number of occurrences of a character ); Converts a string into a character array.
6.sort() sorts the character array in alphabetical order and returns the array
7.reverse() reverses the sorting
8.replace("hello","hello"); string replacement
9.String. prototype.left = function(){
String method extension
}