Copy value of a local variable to a global variable [duplicate]

Question

I have this variable declared in global scope:

export class InboxmanagementComponent implements OnInit {

statmentID: number;   // global variable


displayTaskByIdDetails(){
      this._inboxServcie.getTask(this.task.id).subscribe(
          (data) => {
              this.task = data;
              this.statmentID = data.statmentID;
              console.log('displaying statementId  : ' , this.statmentID); // returns 1 because (data.statementId it's value is 1)
          }
      );
              console.log('displaying statementId  : ' , this.statmentID); // returns undefined
    }
}

So I would liek to copy the value of this.statementID inside arrow function to the global variable