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Array Declaration and Built-in Functions
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(Continued from previous part...)
Dynamic-Size Array Example
To show you how dynamic-size array works, I wrote the following example, array_dynamic_size.html:
<html>
<body>
<!-- array_dynamic_size.html
Copyright (c) 2006 by Dr. Herong Yang. http://www.herongyang.com/
-->
<pre>
<script language="vbscript">
document.writeln("")
Dim aYear()
document.writeln("Check 1: Is aYear an array? " & IsArray(aYear))
' aYear(0) = "Jan" 'Error 1: Subscription out of range
' iSize = UBound(aYear)+1 'Error 2: Index out of range
ReDim aYear(5)
document.writeln("Check 2: Is aYear an array? " & IsArray(aYear))
aYear(0) = "Jan"
aYear(1) = "Feb"
aYear(5) = "Jun"
ReDim Preserve aYear(11)
aYear(10) = "Nov"
document.writeln("Months in a year:")
For i=LBound(aYear) To UBound(aYear)
document.writeln(" " & i & " = " & aYear(i))
Next
</script>
</pre>
</body>
</html>
Here is the output:
Check 1: Is aYear an array? True
Check 2: Is aYear an array? True
Months in a year:
0 = Jan
1 = Feb
2 =
3 =
4 =
5 = Jun
6 =
7 =
8 =
9 =
10 = Nov
11 =
Note that:
- Output message "Check 1" shows that a dynamic-size array is an array event if its size is not set yet.
- Commented out "Error 2" shows that "UBound" can not be used is array's size is not set yet.
"Array" Function and "For Each" Example
To show you how the "Array" function and the "For Each" statement work, I wrote the following example, array_dynamic_size.html:
<html>
<body>
<!-- array_foreach.html
Copyright (c) 2006 by Dr. Herong Yang. http://www.herongyang.com/
-->
<pre>
<script language="vbscript">
document.writeln("")
' Creating a dynamic array with the "Array" function
aSite = Array("yahoo", "netscape", "microsoft")
document.writeln("Is aSite an array? " & IsArray(aSite))
document.writeln("Lower bound of aPrime = " & LBound(aSite))
document.writeln("Upper bound of aPrime = " & UBound(aSite))
' Resizing the array
ReDim Preserve aSite(8)
aSite(8) = "ibm"
' Updating array elements
For Each sSite In aSite
sSite = sSite & ".com"
Next
' Retrieving array elements
document.writeln("Web sites:")
For Each sSite In aSite
document.writeln(" " & sSite )
Next
</script>
</pre>
</body>
</html>
(Continued on next part...)
Part:
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