JavaScript basics and common methods summarizing _javascript skills

JavaScript is an integral part of Ajax technology, so it's important to learn JavaScript well and learn about Ajax and the current popular AJAX framework.

First, the basic knowledge:

1.document.write (""); Output statement
The annotation in 2.JS is//
3. Traditional HTML Document order is:document->html-> (head,body)
4. The DOM order in a browser window is:window-> (navigator,screen,history,location,document)
5. Get the name and value of the element in the form: document.getElementById ("ID number of the element in the form"). Name (or value)
6. A lowercase capitalization JS:document.getElementById ("Output"). Value = document.getElementById ("input"). Value.touppercase ();
Value type in 7.JS: string,number,boolean,null,object,function
The character type in 8.JS converts to a numeric type: parseint (), parsefloat ()
Converts numbers in 9.JS to character type: ("" + variable)
The length of the string in 10.JS is: (length)
The characters in 11.JS are connected with the character story using the + sign.
The comparison operators in 12.JS are: = = equals,!= not equal, >,>=,<.<=
13.JS declaring variable use: var to declare
Judgment statement structure in 14.JS: if (condition) {}else{}
Loop structure in 15.JS: for ([Initial expression];[ Condition]; [Upadte expression]) {Inside loop}
16. The order of the circular abort is: break
function definition in 17.JS: function functionname ([parameter],...) {Statement[s]}
18. When multiple form forms appear in a file, they can be replaced with document.forms[0],document.forms[1].
19. Window: Open Window window.open (), close a window: window.close (), window itself: Self
20. Status bar setting: window.status= "character";
21. Pop-up Message: Window.alert ("character");
22. Pop-up Confirmation Box: window.confirm ();
23. Pop-up Input Prompt box: window.prompt ();
24. Specify the location of the currently displayed link: window.location.href= "URL"
25. Remove the number of forms in the form: document.forms.length
26. Close the output stream of the document: Document.close ();
27. String Append connector: + =
28. Create a document element: Document.createelement (), document.createTextNode ()
29. Methods of obtaining elements: document.getElementById ()
30. Set the value of all text types in the form to null:

var form = Window.document.forms[0] for
(var i = 0; i<form.elements.length;i++) {
if (Form.elements[i].type = = "Text") {
form.elements[i].value = "";
}
}

31. Check the button in JS to determine whether to check: document.forms[0].checkthis.checked (The Checked property represents whether checked returns true or false)
32. Radio button Group (the name of the radio button must be the same): the length of a radio button group Document.forms[0].groupname.length
33. Radio button Group to determine whether the selected is also used checked.
34. Value of the Drop-down list box: Document.forms[0].selectname.options[n].value (n sometimes with a drop-down list box name plus. SelectedIndex to determine the selected value)
35. Definition of string: var myString = new String ("This is Lightsword");
36. String to uppercase: String.touppercase (); The string is turned to lowercase: string.tolowercase ();
37. Returns the position where string 2 appears in string 1: String1.indexof ("String2")!=-1 the description was not found.
38. Takes a character at a specified position in the string: Stringa.charat (9);
39. Remove the substring from the specified start and end point in the string: stringa.substring (2,6);
40. Mathematical function: Math.PI (return to PI), Math.sqrt2 (return to the root), Math.max (value1,value2) return the most in the two number of values, Math.pow (value1,10) return value1 10 times side, Math.Round (value1) rounding function, Math.floor (Math.random () * (n+1)) returns random numbers
41. Define date variables: var today = new Date ();
42. List of date functions: Dateobj.gettime () Gets the time, dateobj.getyear () Gets the year, Dateobj.getfullyear () gets the four-bit year, dateobj.getmonth () Gets the month, Dateobj.getdate () Gets the day, Dateobj.getday () Gets the date, dateobj.gethours () Gets the Hour, dateobj.getminutes () Gets the minute, Dateobj.getseconds () Get seconds, Dateobj.settime (value) set time, Dateobj.setyear (Val) set year, Dateobj.setmonth (Val) set month, Dateobj.setdate (Val) Set day, Dateobj.setday (val) sets the day of the week, Dateobj.sethours set hours, Dateobj.setminutes (val) settings, Dateobj.setseconds (val) Set seconds [Note: This date time starts from 0]
43.FRAME representation: [window.] Frames[n]. objfuncvarname,frames["FrameName"]. Objfuncvarname,framename.objfuncvarname
44.parent represents the Father object, top represents the topmost object
45. Open child window's parent window is: opener
46. Represents the current location: this
47. When calling the JS function in a hyperlink, use: (javascript:) to begin with the following function name
48. Do not perform this js:< in the old browser!--//-->
49. Reference to a file-type Js:<script type= "Text/javascript" src= "Aaa.js" ></script>
50. Specify html:<noscript></noscript> that are displayed in browsers that do not support scripting
51. When the chain and onclick events are sometimes, the old version of the browser turned to a.html, otherwise turn to b.html. Example: <a href= "a.html" onclick= "location.href= ' b.html"; return False ">dfsadf</a>
52.JS of the built-in objects are: Array,boolean,date,error,evalerror,function,math,number,object,rangeerror,referenceerror,regexp, String,syntaxerror,typeerror,urierror
Line wrapping in 53.JS:/n
54. Window Full Screen size: <script>function fullscreen () {This.moveto (0,0); this.outerwidth=screen.availwidth; This.outerheight=screen.availheight;} Window.maximize=fullscreen;</script>
All of the 55.JS represents all the elements of its lower layer
Focus order in 56.JS: document.getElementById ("form Element"). TabIndex = 1
The value of 57.innerHTML is the value of the form element: such as <p id= "para" > "How are <em>you</em>" &LT;/P&GT; the innerHTML value is: How are < Em>you</em>
The value of 58.innerTEXT is the same as above, except that the <em> tag is not displayed.
59.contentEditable can set whether the element can be modified, iscontenteditable returns whether the state can be modified.
60.isDisabled determines whether it is a prohibited state. Disabled setting prohibit state
61.length get length, return integer value
62.addBehavior () is a JS called external function file whose extension is. htc
63.window.focus () causes the current window to precede all windows.
64.blur () refers to the loss of focus.
65.select () refers to the element as a selected state.
66. Prevent users from entering text in text boxes: onfocus= "This.blur ()"
67. Remove the number of occurrences of the element in the page: Document.all.tags ("div (or other HTML tag)"). length
There are two forms of output in 68.JS: Modal and modeless. window.showModalDialog (), window.showmodeless ()
69. Status bar text settings: window.status= ' text ', the default status bar text settings: window.defaultstatus = ' text. '
70. Add to Favorites: External. Addfavorite ("http://www.dannyg.com", "Jaskdlf");
71.JS No action is encountered in scripting errors: Window.onerror = donothing; The syntax for the specified error handle is: Window.onerror = HandleError;
72.JS Specifies the parent window for the currently open window: Window.opener, support Opener.opener ... The multiplicity continues.
Self in 73.JS refers to the current window
74.JS status bar display content: window.status= "Content"
Top in 75.JS refers to the topmost frame in the frameset
Close the current window in 76.JS: Window.close ();
77.JS box for confirmation: if (Confirm ("Are you sure?") {Alert ("OK");} Else{alert ("not OK");}
Window redirection in 78.JS: Window.navigate ("http://www.sina.com.cn");
Printing in 79.JS: Window.print ()
80.JS prompt input box: window.prompt ("message", "defaultreply");
Window scroll bar in 81.JS: Window.Scroll (x,y)
The window in 82.JS scrolls to position: Window.scrollby
Set time interval in 83.JS: setinterval ("expr", Msecdelay) or setinterval (Funcref,msecdelay) or settimeout
The modal in 84.JS is displayed in the ie4+ line, not in nn: ShowModalDialog ("URL" [, Arguments][,features]);
Handle used before exiting in 85.JS: function Verifyclose () {event.returnvalue= "We really like you and hope your'll stay longer."} Window.onbeforeunload=verifyclose;
86. File handle to use when the form is first called: onload ()
87. File handle to call when form closes: OnUnload ()
88.window.location Properties: Protocol (http:), hostname (www.example.com), port (+), host (www.example.com:80), pathname ("/A /a.html "), hash (" #giantGizmo ", means jump to the corresponding anchor), href (All information)
89.window.location.reload () refreshes the current page.
89-1.parent.location.reload () Refreshes the Father object (for frames)
89-2.opener.location.reload () Refreshes the parent window object (for a single open window)
89-3.top.location.reload () Refreshes the topmost object (for multiple windows)
90.window.history.back () returns to the previous page, Window.history.forward () returns to the next page, Window.history.go (returns to page, or uses the visited URL)
91.document.write () No line-wrapping output, Document.writeln () line-wrapping output
92.document.body.nowrap=true prevents link text from wrapping.
93. Variable name. CharAt (ordinal), take the first few characters of the variable.
The "ABC". charCodeAt (ordinal number) returns the ASCII value of the first few characters.
95. String Connection: String.Concat (string2), or connect with + =
96. Variable. IndexOf ("character", starting position), returns the first occurrence of the position (calculated starting from 0)
97.string.lastindexof (Searchstring[,startindex]) where the last occurrence occurred.
98.string.match (regexpression) to determine whether characters match.
99.string.replace (regexpression,replacestring) replaces the existing string.
100.string.split (delimiter) returns an array to store the value.
101.string.substr (Start[,length]) takes a string from the first few to the specified length.
102.string.tolowercase () causes the string to be all lowercase.
103.string.touppercase () turns all characters into uppercase.
104.parseInt (String[,radix)] forces the conversion to an integral type.
105.parseFloat (String[,radix]) is cast to a floating-point type.
106.isNaN (variable): test for numeric type.
107. Define Constants Keywords: const, define variables keywords: var

Two: JavaScript common methods are as follows:

1.index and IndexOf, LastIndexOf

var arr = [1,2,3,4,5,4,3,2,1];
1 parameters when the value is passed, return the index position (index zero-based)
var index = arr.indexof (4);
2 parameters, the first parameter represents the starting position, the second parameter or the value
var index = arr.indexof (4,4);
Alert (Index)//5

2. Five new superposition methods