Array: an ordered collection of series elements
property:
length: used to obtain the number of array elements, with the maximum subscript plus 1
method:
sort(function): If the sort number is not specified, it is arranged in alphabetical order of the elements. If it is not a string type, it is converted into a string and sorted;
reverse(): reverse the order of elements in the array;
concat(array1,arrayn): used to combine N arrays into array1;
join(string): used to merge elements in an array into strings. string is a delimiter. If the parameters are omitted, they will be merged directly without delimiting;
slice(start,stop): is used to return elements from start to stop in the array. If the parameter is negative, it means the countdown start or stop elements;
toString(): Return all elements of the array to a string separated by commas;
string
property:
length: used to return the length of the string, and the usage is the same as that of an array;
method:
anchor(): This method creates a tag like anchor in HTML, with the format <a name="" .....> , accessed through the following method (chorName)
toUpperCase(): Convert string to uppercase;
toLowerCase(): Convert string to lowercase;
indexOf(a,b): Find the position where character a appears in the string from the b-th character and returns. If b is omitted, it is searched from the position 0 by default;
charAt(i): Returns the i-th character in the string;
substring(start,end): Returns all characters in the string from start - end (but does not return the character end itself);
sub(): Display the specified string in subscript format;
Date: See the detailed demonstration
Definition method:
a: var newdt=new Date() -->Create the time object and assign the value to the current time;
b: var newdt=new Date(milliseconds) --> Create a time object, and set the value of the object with the delay time of GTM, in milliseconds;
c: var newdt=new Date(string) --> Use a specific time string to assign values to the newly created time object, and its format matches the parse method of the Date object;
d: var newdt=new Date(year, month, day, hour, minute, second, millisecond) --> Assign values to the object in the order of year, month, day, hour, minute, second, millisecond;
Method: Get time; set time; format conversion
A: Get time
getDate() ----get the current full time;
getYear()------get the current year
getMonths()---get the current month
getDay()-------get the current date
getHours()----get the current hour
getMinutes()---get the current minute
getSeconds()---get the current second
getTime()-----get the current time, unit to seconds
getTimeZoneOffset-get the current time zone offset information
b: Set time
Compare the above obtaining and replace get with set, for example getDate() ---> setDate()
c:Conversion method
toGTMString() ------Converted to a string of Greenwich Standard Time expressions;
toLocaleString()----Convert to a string expressed in local time
toString()--------------------Convert time to string
parse-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
UTC-----------------------------Returns the gap from Greenwich Standard Time to the specified time in milliseconds
Math Math:
Attribute: Note that attributes in mathematical objects refer to read
E (=2.7182) ------The base of natural logarithm (I don’t understand the specific meaning, alas, I don’t understand the things closely related to mathematics, I’m depressed!)
LN10(=2.30259) --- the natural logarithm of 10;
LN2(=0.69315)------------------------------------------------------------------------------------------------------------------
PI(=3.1415926)---Pi
SQRT1_2(=0.7071)---Square Root of 1/2
SQRT2(=1.4142)------------------------------------------------------------------------------------------------------------------
LOG2E(=1.44269)---Base 2, the logarithm of E
LOG10E(=0.43429)--Log-number with base 10 E
Method: Actually, it’s not much to use, so let’s get it all out
sin(a) --- Find the sine value of a
cos(a)----- Find the cosine value of a
tan(a)----- Find the tangent value of a
asin(a)----- Find the inverse sine value of a
atan(a)----- Find the inverse cosine value of a
exp(a)------ Find the index of a
log(a)------ Find the natural logarithm of a
Pow(a,i)---- Find the power of a (multiplier)
round(a)----round a
sqrt(a)---- Find the square root of a
abs(a)------ Find the absolute value of a
random()----Get random number
max(a,b)---take the larger number
min(a,b)---take the smaller number
Note: The parameters of the function are all floating point types, and the parameters of the trigonometric function are radian values, not degrees.
JavaScript built-in functions
escape() and unescape(): Encoding and decoding a string
eval(string): used to perform operations or statements represented by strings
For example: var a=0; var str1="a+=a"; eval(str1);
parseInt() and parseFloat(): Convert the value of the text box to an integer or a floating point number
Note: parseInt() does not round the number, but cuts the tail
isNaN(): The complete E text is (is not a number), as the name implies, it is to determine whether a string is a number, such as if(isNaN("Tianbobiao series tutorial"))
Custom object: There are two methods: initializing the object and defining the constructor object.
a: Initialize the object
For example: Object ={Property 1: Value 1;Property 2: Value 2;...Property n: Value n}, note that each property\value pair is separated by a semicolon;
b: Object that defines the constructor
For example:
function function name (property 1,property 2,...property N){
this.Attribute 1=Attribute value 1;
this.Attribute 2=Attribute value 2;
this.Attribute n=Attribute value n;
this.Method name 1 = Function name 1;
this.Method name 2=function name 2;
}
Note: The method name and function name can be the same name, but before the method calls the function, the function must be defined, otherwise an error will occur.
Creating a new instance for a custom function is also done using the new statement.
Browser Objects
window object:He is at the central level and is at the highest level of all objects. To put it bluntly, without him, you will have nothing to play;
property:
closed------------------------------------------------------------------------------------------------------------------------------
er------------Storage the parent window of the() method to open the window;
defaultstatus---the information displayed by the status bar by default;
status------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Document, Location, History---It's very important, I will talk about it in detail later. If you don't want to wait, just look here
method:
alert(text)-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
confirm(text)-----------------Confirmation information box, the parameters are confirmation information
prompt(text,default)----The input dialog box pops up, the parameters are prompt information and default values
document object:Including various characteristics of the current web page, such as title\URL\background\language\modification time, etc.
property:
title------------------------------------------------------------------------------------------------------------------------------
lastModified-------Last time for file modification
URL------------------------------------------------------------------------------------------------------------------------------
Cookies----------------------------------------------------------------------------------------------------------------------------
bgColor---------------------------------------------------------------------------------------------------------------------------
fgColor---------------------------------------------------------------------------------------------------------------------------
location----------Save all page address information of the document
alinkcolor----------------------------------------------------------------------------------------------------------------------------
linkcolor-----------------------------------------------------------------------------------------------------------------------------
vlinkcolor----------------------------------------------------------------------------------------------------------------------------
method:
write(text)----Write text or labels to the document without changing lines
writeln(text)---Write text or label to the document and wrap the line at the last character
()----------Open a new document, for example ("Address", "Window Name", "Style")
close()--------------Close the current document
Location object:Contains all page address information of the current document
property:
protocol------------------------------------------------------------------------------------------------------------------------------
host------------------------------------------------------------------------------------------------------------------------------
port------------------------------------------------------------------------------------------------------------------------------
pathname-----------------------------------------------------------------------------------------------------------------------------
hash-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
search------------------------------------------------------------------------------------------------------------------------------
hostname-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
href----------------------------------------------------------------------------------------------------------------------------
method:
assign(URL)------Navigate the page to another address
reload-----------------------Refresh the page
replace(URL)-------Replace the current page with the specified URL
History：This object includes URL information that has been visited before
Attribute: length, return the number of URLs
The method is mainly go(n) , and the relative page is loaded through this method