196
Chapter 10: Writing and Calling User-Defined Functions
Using the Arguments scope as an array
The following rules apply to referencing Arguments scope as an array:
•
If you call the function using unnamed arguments, the array index is the position of the
argument in the function call.
•
If you use names to pass the arguments, the array indexes correspond to the order in which the
arguments are declared in the function definition.
•
If you use names to pass arguments, and do not pass all the arguments defined in the function,
the Arguments array has an empty entry at the index corresponding to the argument that was
not passed. This rule applies only to functions created using the
cffunction
tag.
•
If you use a name to pass an optional argument that is not declared in the function definition,
the array index of the argument is the sum of the following:
a
The number of arguments defined with names in the function.
b
The position of the optional argument among the arguments passed in that do not have
names defined in the function.
However, using argument names in this manner is not good programming practice because
you cannot ensure that you always use the same optional argument names when calling the
function.
To demonstrate these rules, define a simple function that displays the contents of its Arguments
array and call the function with various argument combinations, as shown in the following
example:
<cffunction name="TestFunction" >
<cfargument name="Arg1">
<cfargument name="Arg2">
<cfloop index="i" from="1" to="#ArrayLen(Arguments)#">
<cfoutput>Argument #i#: #Arguments[i]#<br></cfoutput>
</cfloop>
</cffunction>
<strong>One Unnamed argument</strong><br>
<cfset TestFunction(1)>
<strong>Two Unnamed arguments</strong><br>
<cfset TestFunction(1, 2)>
<strong>Three Unnamed arguments</strong><br>
<cfset TestFunction(1, 2, 3)>
<strong>Arg1:</strong><br>
<cfset TestFunction(Arg1=8)>
<strong>Arg2:</strong><br>
<cfset TestFunction(Arg2=9)>
<strong>Arg1=8, Arg2=9:</strong><br>
<cfset TestFunction(Arg1=8, Arg2=9)>
<strong>Arg2=6, Arg1=7</strong><br>
<cfset TestFunction(Arg2=6, Arg1=7)>
<strong>Arg1=8, Arg2=9, Arg3=10:</strong><br>
<cfset TestFunction(Arg1=8, Arg2=9, Arg3=10)>
<strong>Arg2=6, Arg3=99, Arg1=7</strong><br>
<cfset TestFunction(Arg2=6, Arg3=99, Arg1=7)>
Note:
Although you can use the Arguments scope as an array, the
IsArray(Arguments)
function
always returns false and the
cfdump
tag displays the scope as a structure.
Содержание COLDFUSION MX 61-DEVELOPING COLDFUSION MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...