安全的取对象属性

let data = {
    products_id:12,
    products_name:'name',
    price:{
        vip1:100,
        vip2:200
    }
}

console.log( data.products_id || '')    // 12
console.log( data.products_name || '')    // name
console.log( data.products_date || '')    // ''

console.log( (data.price || {})['vip1'] || '' )    // 100
console.log( (data.price || {})['vip2'] || '' )    // 200
console.log( (data.price || {})['vip3'] || '' )    // ''