xpath exist boolean()

boolean() 으로 특정 element를 조회하면 될 듯?

 

[링크 : https://stackoverflow.com/questions/5689966/how-to-check-if-an-element-exists-in-the-xml-using-xpath]

 

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2019.12.17

옛날 글이라 그런가 링크가 깨졌네

The boolean function converts its argument to a boolean as follows: a number is true if and only if it is neither positive or negative zero nor NaN a node-set is true if and only if it is non-empty a string is true if and only if its length is non-zero an object of a type other than the four basic types is converted to a boolean in a way that is dependent on that type

[링크 : https://stackoverflow.com/questions/5689966/how-to-check-if-an-element-exists-in-the-xml-using-xpath]

[링크 : http://www.w3.org/TR/xpath/#function-boolean] << 옛날 링크

 

Rules The function computes the effective boolean value of a sequence, defined according to the following rules. See also Section 2.4.3 Effective Boolean Value XP31. If $arg is the empty sequence, fn:boolean returns false. If $arg is a sequence whose first item is a node, fn:boolean returns true. If $arg is a singleton value of type xs:boolean or a derived from xs:boolean, fn:boolean returns $arg. If $arg is a singleton value of type xs:string or a type derived from xs:string, xs:anyURI or a type derived from xs:anyURI, or xs:untypedAtomic, fn:boolean returns false if the operand value has zero length; otherwise it returns true. If $arg is a singleton value of any numeric type or a type derived from a numeric type, fn:boolean returns false if the operand value is NaN or is numerically equal to zero; otherwise it returns true.

[링크 : https://www.w3.org/TR/xpath-functions-31/#func-boolean] << 새로운 링크?