答：不一定，可以是对象，vue文档中表述有误导性而已，他自己的例子里也有对象的形式
function initData(vm){
let data = vm.$options.data
data = vm._data = typeof data === ‘function’ ? getData(data, vm) : data || {}
/*
Because here，data is a reference from vm.$options.data，
if data is an object,
when there are many instances of this Component,
they all use the same `data`
if data is a function, Vue will use method getData( a wrapper to executing data function, adds some error handling)
and return a new object, this object just belongs to current vm you are initializing
*/
……
// observing data
observe(data, true)
}
内容来自：https://stackoverflow.com/a/61184547/17160403
标签：function,use,函数,object,vm,vue2,data From： https://www.cnblogs.com/dou-fu-gan/p/17112403.html