PHP How to read XML Child Node Value in a String using PHP?

[mortal7]

I have a String which gets its value dynamically from other server.Value of string is\[code\]$string1 = '<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.microsoft.com/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <soap:Body> <AuthenticateUserResponse xmlns="http://microsoft.com/xml/namespace/2012/04"> <Authenticator>AE1001</Authenticator> </AuthenticateUserResponse> </soap:Body></soap:Envelope>';\[/code\]My Question is, generally we use *$xml = simplexml_load_file("test1.xml");* to load XML files, but here in my requirement it is a String, how can i read this String value and extract the child node and its value? Example:\[code\]<Authenticator> and its value "AE1001" ?\[/code\]Is there a way to put this into Array? so that its easy for me to print out its node value?