javascript - Calling a function in the page constructor results in empty array -

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• how return response asynchronous call? 21 answers

i try load , bind this.studentnames[i].checked prepare checkboxes (key-value pair in localstorage if checkbox set). however, after correctly pushing entries storage in this.studentnames array (i can see of them in storage in view), this.studentnames array empty [] in array , hence not longer accessable model.

do use here in wrong way? thought, when use =>functions, erverything should ok?!

my view (html):

<ion-list>   <ion-item *ngfor="let studentname of studentnames; let i=index">     <ion-label>{{studentname.name}}</ion-label>     <ion-checkbox [(ngmodel)]="studentname.checked" (ionchange)="checkboxtoggle($event,studentname)"></ion-checkbox>   </ion-item> </ion-list> 

my model (typescript):

@mycomp... selecteditem: any; studentnames: array<{id: string, name: string, checked: boolean}>;  constructor(private navparams: navparams, public storage: storage) {     // if navigated page, have item available nav param     this.selecteditem = navparams.get('item');     this.studentnames = [];     this.readstorageatstartup();     console.log(this.studentnames)   }    public readstorageatstartup() {     this.storage.ready().then(() => {        this.storage.foreach( (value: string, key: string, index: number) => {          if(key.charat(0)=="s") {            this.studentnames.push({id: key, name: value, checked: true})          }        })     })   } 

console.log() (firefox):

array [  ] 

thanks help!

pass storage parameter readstorageatstartup function , resolve asynchronous request there

public readstorageatstartup(storage: storage) { storage.ready().then(() => {    storage.foreach( (value: string, key: string, index: number) => {      if(key.charat(0)=="s") {        this.studentnames.push({id: key, name: value, checked: true})      }    }) }) 

}