need help with xpath expression

Question

I have an xml node that looks like <slot highcount="20" lowcount="10" />

I've tried the following xpath expression:

XmlNode node = xdoc.SelectSingleNode("slot[@lowcount>=12] && slot[@highcount <=12]");

but I get an invalid token error and I don't have enough experience with this to know what I'm doing wrong. Any ideas?

Answer 1

You need to use the "and" operator - there is no "&&" operator in XPath. I think something like this should work:

XmlNode node = xdoc.SelectSingleNode("slot[@lowcount>=12 and @highcount <=12]");

EDIT: This is the correct syntax, but to select the node specified in the question, we need to flip around the operators like the second snippet below. I'm leaving the original code sample in for context, so that the comment thread makes sense:

XmlNode node = xdoc.SelectSingleNode("slot[@lowcount<=12 and @highcount >=12]");

Answer 2

XPath doesn't use && and ||; it uses and and or.

3.6 Logical Expressions

A logical expression is either an and-expression or an or-expression. If a logical expression does not raise an error, its value is always one of the boolean values true or false.

 [8]      OrExpr  ::= AndExpr ( "or" AndExpr )*
 [9]      AndExpr ::= ComparisonExpr ( "and" ComparisonExpr )*

References

• Xpath 2.0 Specification/Logical Expressions