while
Syntax
while (expression) { /* body */ }
Description
Repeatedly execute a block of statements until
the specified condition evaluates to false
. The condition is an XPath expression that is converted to a boolean
type. If the expression evaluates to true
, the contents of the while loop are executed. The loop continues
to execute until the expression evaluates to false
. During execution, the context is not changed. In the expression,
you should use a mutable variable, which is declared using the mvar
statement, to avoid creating an infinite loop.
Attributes
expression |
XPath expression, which is cast to boolean
type and used as the condition for the while loop. The code block
contents are executed as long as the condition evaluates to |
SLAX Example
In the example, the while loop parses through the item
list until the desired value is found. When that value is detected, $seen
is set to true, and the while loop exits.
mvar $seen = false(); mvar $count = 1; while (not($seen)) { if (item[$count]/value) { set $seen = true(); } set $count = $count + 1; }
Release Information
Statement introduced in version 1.1 of the SLAX language, which is supported in Junos OS Release 12.2 and later releases.