Questions about JS data types

when I was working on a company project, a piece of data came from the background: [{. }]
I take it for granted that it is an array, then assign it to an empty array aprData, and pass aprData to the subcomponents, and specify type checking in the subcomponents: 

props: {
    aprData:[],
    }

and then something amazing happens, and the console says: 

errorHandler: I**nvalid prop: type check failed for prop "aprData". Expected , got Array

so I hastened to check the data type: 

console.log("aprData:",Object.prototype.toString.call(this.aprData));

result: aprData type: [object Array]
so I am completely confused. What went wrong?

Javascript vue.js
Mar.03,2022

because your type checking should write 

props: {
    aprData: Array
    ...
}

I haven't written VUE, for a long time, but props type constraint, shouldn't I write "Array"? 

props:{
    aprData:Array
}
There is no such way to write

, any of the following is fine. 

// 
props: ['aprData']

// 
props: {
    aprData: Array
}

// 
props: {
    aprData: {
        type: Array,
        default: []
    }
}

replace [] with Array

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