javascript - Save DZ.api response in variable -

using code below can console.log response in function(response) part, not in second console.log. how can extract string out of dz.api , child/any variable, when using dzsearch function?

@injectable() export class deezerservice{   child:any;    constructor(){     new dz.init({       appid  : 'appid',       channelurl : 'https://localhost:4200/src/channel.html'     });   }    dzsearch(){     console.log('testing dzsearch() init');     this.child = dz.api('/album/12720342/tracks', function(response){       console.log(response.data[0].title)       return response.data[0].title;       });      console.log(this.child);   } }