Beginner's introduction: JavaScript Usage tips

Javascript| Tips

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 ("I

Nput "). 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],...)

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 if (Form.elements.type = = "Text") {

Form.elements.value = "";

}

}

31. Check the button in JS to determine whether to check: document.forms[0].checkthis.checked (checked property for whether or not selected

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 is sometimes added with a drop-down list box name. sel

Ectedindex 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 pi), Math.sqrt2 (return to the root), Math.max (value1,value2) returns the two number of the most

At the value, Math.pow (value1,10) returns the value1 10-second square, Math.Round (value1) rounding function, Math.floor (math.ra

Ndom () * (n+1)) returns a random number

41. Define date variables: var today = new Date ();

42. Date Function List: Dateobj.gettime () Get Time, dateobj.getyear () Get the Year, Dateobj.getfullyear () get

Four-bit year, dateobj.getmonth () Gets the month, dateobj.getdate () Gets the day, Dateobj.getday () Gets the date, dat

Eobj.gethours () Gets the Hour, dateobj.getminutes () Gets the score, dateobj.getseconds () Gets the second, Dateobj.setti

Me (value) set time, Dateobj.setyear (Val) set year, Dateobj.setmonth (Val) set month, Dateobj.setdate (VA

L) Set Day, Dateobj.setday (val) set days of the week, Dateobj.sethours set hours, Dateobj.setminutes (Val) set points,

Dateobj.setseconds (val) Set seconds [Note: This date time starts at 0]

43.FRAME representation: [window.] Frames[n]. objfuncvarname,frames["FrameName"]. Objfuncvarn

Ame,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: (JavaScript:) to start with the following function name

48. Do not execute this JS in the old browser:

49. Refer to a file-style JS:

50. Specify HTML to display 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: DFSADF

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:

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:

"How are"

, the value of innerHTML is: How to Are You

The value of 58.innerTEXT is the same as above, except that it does not show the mark.

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 the text box:

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" t;, "JASKDLF");

71.JS No action is encountered in scripting errors: Window.onerror = donothing; The syntax for the specified error handle is: Window.on

Error = 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?") Else{alert ("not OK");}

Window redirection in 78.JS: Window.navigate ("http://www.sina.com.cn" t;);

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 Settimeou

T

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 Ho

PE you'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 (example.com), Port (e), host

XAMPLE.COM:80), pathname ("/a/a.html"), hash ("#giantGizmo", which means to jump to the corresponding anchor), href (all the letters

Income

89.window.location.reload () refreshes the current page.

90.window.history.back () returns to the previous page, Window.history.forward () returns to the next page, Window.history.go (returns

page, also use the URL you have visited

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