Can someone explain this javascript code to me?

var vTableExp = "//a[contains(@href,开发者_如何学编程'newdid')]/ancestor::td/ancestor::tr/ancestor::tbody";
var vTable = dom.find(vTableExp, XPFirst);

thanks

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It is an XPATH searching against the DOM, looking for wrapping <TBODY> elements which have a descendant <a> whose href contains "newdid".

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It finds the first tbody which is an ancestor of a a tr element which is an ancestor of a td element which is an ancestor of an a element whose href contains the string newdid. (IOW, assuming that the parsed document is (X)HTML, select the body of the first table that has a cell containing a link whose address contains the string newdid.)

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vTableExp is probably a regexp pattern and then it's being searched for.