how to pass variables between functions ionic 3

Question

First I have to say that I am new on ionic, angular, typescript, and I don´t know the better way to do this project, so have mercy please.

I get a string from a txt file and save it on the variable estado, then I want to use that string with another function but I only get undefined, some help please.

import { Component } from '@angular/core';
import { NavController, NavParams } from 'ionic-angular';
import * as jQuery from 'jquery';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  estado: string;
  estadoView: string = " deshabilitadas";
  accionView: string = "Activar";

  constructor(public navCtrl: NavController, public navParams: NavParams) {
  }

  ionViewDidLoad() {

    jQuery.get('http://localhost/estadoAlarma.txt', function (estado) {
      console.log("ionviewdid");
      console.log(estado);
      return estado;
   });
    this.actAlarma(this.estado);
}

actAlarma(estado) {
      console.log(estado); //here I get undefined
    if (estado == "activado" ) {
      console.log("si vale");
      this.estadoView=" habilitadas";
      this.accionView="Desactivar1";
    }
    else{
      console.log("no vale");
      this.estadoView=" deshabilitadas";
      this.accionView="Activar";
    }
}
}