getPrice(strCode: string) {
    if (strCode == "" || strCode == undefined) {
      this.showMessage("strCode is missing");
      return {"price": 0, "percentChange": 0};
    } else {
      let loading = this.loadingCtrl.create({
        content: 'Please wait...',
        spinner: 'dots'
      });
      loading.present();
      this.restProvider.getItemPrice(strCode).subscribe(priceInfo => {
        loading.dismiss();
        this.priceInfo = priceInfo;
        if (this.priceInfo.failed != "") {
          this.showMessage("Failed to find " + this.priceInfo.failed);
          return {"price": 0, "percentChange": 0};
        } else {
          return {"price": this.priceInfo.response[0].price, "percentChange": this.priceInfo.response[0].percent_change};
        }
      });
    }
  }

<button ion-button (click)="getPrice()">Get Price</button>

  getPrice() {
    let priceInfo1;
    new Promise((resolve) => {this.helper.getPrice(this.transactionInfo.strCode)}).then(
      priceInfo => {
        priceInfo1 = priceInfo;
        this.transactionInfo.itemPrice = priceInfo1.price;
      });
  }

let priceInfo = this.helper.getPrice(itemInfo.strCode);