php - Laravel and vue pass array to prop -

i've got multiselect component looks this:

 <multi-select prp-selected="<?php old('organisations_working_at') ?>"               prp-name="organisations_working_at"               :prp-options="{{ json_encode($organisations) }}"               prp-placeholder="kies organisatie(s)"> </multi-select> 

as can see pass old('organisations_working_at') value laravel.

my component looks (i made wrapper around multi-select):

<template>     <div>         <input type="hidden" v-for="select in selected" :name="prpname + '[]'" :value="select.id">          <multiselect                 v-model="selected"                 :multiple="true"                 :options="prpoptions"                 :custom-label="prpcustomlabel"                 :placeholder="prpplaceholder"                 track-by="id"                 selectlabel="druk op enter en voeg toe"                 deselectlabel="druk op enter en verwijder"                 open-direction="top"                 @select="select"                 @remove="remove">         </multiselect>     </div> </template>  <script>     import multiselect 'vue-multiselect';      export default {         components: { multiselect },          props: {             prpselected: {                 type: array,                 default: this.selected,             },              prpoptions: {                 type: array,                 default: this.options,             },              prpcustomlabel: {                 type: function,                 default: (label) => label.name,             },              prpplaceholder: {                 type: string,                 default: "kies items"             },              prpname: {                 type: string,                 default: "items"             }         },          created() {             this.selected = this.prpselected;         },          data() {             return {                 selected: [],                 options: []             }         },           methods: {             select(value) {                 this.$emit('optionadded', value.id);             },              remove(value) {                 this.$emit('optionremoved', value.id);             }         }     } </script> 

but when vue devtools selected (when receive failed validation response laravel):

selected:"" 

when dd(old('organisations_working_at')); not empty , array.

what doing wrong?

i believe need set prop like:

prpselected: { type: array, default: [] }

and return data it's:

selected: this.prpselected ? this.prpselected : []