JavaScript

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JavaScript
Lance Cohen, Ph.D. Molloy College
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SCRIPT tag

• ltSCRIPT LANGUAGEJavaScriptgt
• lt/SCRIPTgt

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ltNOSCRIPTgt

• Warn users their Web browsers do not understand
  JavaScript
• ltNOSCRIPTgt
• ltHRgtYour Web browser doesnt speak
  Javascript!ltHRgt
• lt/NOSCRIPTgt

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Write ltdocument.writelngt

• Use document.writeln to print
• document.writeln(X is x)
• document.writeln(Count is , count)
• document.writeln(Hello, world!)

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For Loop

• For (initial exp condition update exp)
• statements
• for(var I 0 I lt 9 I)
• document.writeln(I)

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IfElse

• If (condition)
• statements
• else
• statements

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IfElse

• If(message.IsEncrypted( ))
• Message.Decrypt(SecretKey))
• else
• Message.Display( )

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Function

• Function name(paramater)
• statements
• function square(x)
• return x x

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Alert

• INPUT TYPEbutton NAMEbutton1 ValueDont
  Press!onclickalert(Dont Press Me)gt
• Users must dismiss this dialogue box
• before going forward.

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Confirm
confirm(Do you agree?)

• Puts up dialog box
• Two buttons OK and Cancel
• Users must click on one or the other
• Returns true or false

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Prompt
prompt(Give me your URL, faculty.molloy.edu)

• Provides a text box
• Users insert text
• Can provide a default string
• Returns a value

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Location

• Location object holds the current URL
• Control browsing from within JavaScript
• location.hrefhttp//faculty.molloy.edu/lcohen

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Status Bar

• Holds value in the status bar below the main
  screen
• window.defaultStatus"Help your reader!

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Open a Window

• JavaScript can create a new window automatically.
• window.open(text.htm,New Window,width300,hei
  ght250)

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• Signing off