MACROMEDIA ColdFusion MX, Develop Manual, Page: 138 / 860

138 Chapter 6: Extending ColdFusion Pages with CFML Scripting
Note: Unlike the
cfloop
tag, CFScript for-in loops do not provide built-in support for looping over
queries and lists.
Using continue and break statements
The continue and break statements enable you to control the processing inside loops:
•
The
continue
statement tells ColdFusion to skip to the beginning of the next loop iteration.
•
The
break
statement exits the current loop or
case
statement.
Using continue
The
continue
statement ends the current loop iteration, skips any code following it in the loop,
and jumps to the beginning of the next loop iteration. For example, the following code loops
through an array and display’s each value that is not an empty string:
for ( loop=1; loop LE 10; loop = loop+1) {
if(a[loop] EQ "") continue;
WriteOutput(loop);
}
(To test this code snippet, you must first create an array, a, with 10 or more elements, some of
which are not empty strings.)
In general, the
continue
statement is particularly useful if you loop over arrays or structures and
you want to skip processing for array elements or structure members with specific values, such as
the empty string.
Using break
The
break
statement exits the current loop or
case
statement. Processing continues at the next
CFScript statement. You end
case
statement processing blocks with a
break
statement. You can
also use a test case with a
break
statement to prevent infinite loops, as shown in the following
example. This script loops through an array and prints out the array indexes that contain the
value key. It uses a conditional test and a
break
statement to make sure that the loop ends when
at the end of the array.
strings=ArrayNew(1);
ArraySet(strings, 1, 10, "lock");
strings[5]="key";
strings[9]="key";
indx=0;
for( ; ; ) {
indx=indx+1;
if(Find("key",strings[indx],1)) {
WriteOutput("Found a key at " & indx & ".<br>");
}
else if (indx IS ArrayLen(strings)) {
WriteOutput("Array ends at index " & indx & ".<br>");
break;
}
}