node.js - Deleting an object from a array in javascript -

i'm trying remove object cart using art_id, when i'm getting error syntaxerror: delete of unqualified identifier in strict mode. why happening , how can modify code come on error

 function remove_from_cart(req, res, next) {         console.log(req.session);         var art_id = req.params._id;          var art_to_remove = _.findwhere(req.session.cart, {             art_id: art_id         });          console.log(art_to_remove);         delete art_to_remove;         console.log(req.session);         res.send('deleted')     } 

since seems you're using underscore, can use _.reject():

req.session.cart = _.reject(req.session.cart, { art_id: art_id });