笔试单选

单选题:

1,

(function(callback){
    city = {name: 'hangzhou'};
    callback(city);
})(function(obj){
    obj.name = "shanghai";
    obj = {name: "beijing"};
});
console.log(city.name);   //"shanghai"

2,

const {defineProperty, freeze} = Object;
const run = fn => {
    try {
        fn();
    } catch(e){
    }
}
Object.prototype.name = 'Anonymous';
let user = {
    name: 'James',
}
const constUser = {
    name:'Musker'
}
run(() => defineProperty(user, 'name', {
    writable: false,
    value:'Basin',
}));
run(() => user.name = 'Lily')
run(() => user = {name:'Helios'})
run(() => user = constUser)
run(() => user.name = 'Peggy')
run(() => user = freeze({name:'Karmen'}))
run(() => user.name = 'Vienna')
run(() => delete user.name)
console.log(user.name); //  "Karmen"

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转载自www.cnblogs.com/songya/p/9656565.html