JavaScript Arrays and String basics

Some common usages and exercises of arrays

Array.concat () connection array

Practice:

var arr=[1,2,3,4,5];
ARR1=[7,8,9];
document.write (Arr.concat (arr1[0))//Return 1,2,3,4,5,7
Array.join () joins the array elements to construct a string.

The size of the Array.Length array

Array.pop () deletes and returns the last element of the array

Practice:
var arr=[1,2,3,4,5]
document.write (Arr.pop ());//Return 5
document.write ("</br>" +arr);//Return 1,2,3,4

Array.push () Adding elements to an array

Array.reverse () Reverses the order of the elements in the array
Practice:
var arr=[1,2,3,4,5]
Arr.reverse ();
document.write (arr); return 5,4,3,2,1

Array.shift () moves an element to an array
Practice:
var arr=[1,2,3,4,5];
Arr.shift ();
document.write (arr); return 2,3,4,5

Array.slice () returns part of an array

Practice:

var arr=[1,2,3,4,5];
document.write (Arr.slice (0,3)); return to

Array.Sort () sorting an array element

Array.splice () Inserting, deleting, or replacing elements of an array

Practice:

Syntax: Array.splice (Start, DeleteCount, value, ...)

var arr=[1,2,3,4,5];
ARR1=[7,8,9];
Arr.splice (0,2,12,23);
document.write (arr);//Return 12,23,3,4,5


Array.tolocalestring () converts an array to a local string

Array.tostring () converts an array to a string

Array.unshift () Inserts an element at the head of the array

some common usages of string practice

String.charat () returns the nth character in a string
Practice:
var str= "Gagtrhst";
Str.charat (2); return g
String.charcodeat () code that returns the nth character in a string

String.Concat () connection string

String.fromCharCode () Create from character encoding-a string

String.IndexOf () Retrieving strings

String.LastIndexOf () Retrieves a string from the back forward
Practice:

var str= "Gagtrhst";
Str.lastindexof ("HST" [2]); return 7
String.Length Length of string

String.localecompare () compares two strings in a local-specific order

String.match () finds the match of one or more regular expressions

String.Replace () replaces a substring that matches a regular expression
Practice:

var str= "Gagtrhst";
document.write (Str.replace ("G", ' a ')); Replace the first G with a

String.search () Retrieves a substring that matches a regular expression
Practice:
var s = "JavaScript is fun";
document.write (S.search (/script/i)); Returns the position of the first character of the first matched substring

String.slice () Extracts a child
Practice:
var s = "ABCDEFG";
S.slice (0,4)//Return to "ABCD"

String.Split () splits a string into a string array
Practice:
var str= "Gagtrhst";
document.write (Str.split ("", 3)); return g,a,g
"1:2:3:4:5". Split (":"); return ["1", "2", "3", "4", "5"]

STRING.SUBSTR () Extracts a substring
Practice:

var str= "Gagtrhst";
Alert (STR.SUBSTR (2,2)); return to GT
String.substring () returns a substring of a string

String.tolocalelowercase () Converts a string to lowercase

String.tolocaleuppercase () Converts a string to uppercase

String.tolowercase () Converts a string to a small

JavaScript Arrays and String basics