Php 如何从对象读取特定数据？

{“TransactionInfo”：{“日期”：“06\/04\/2018”，“时间”：“09:29东部时间”，“交易费用”：{“货币价值”：“0.00”，“货币代码”：{}}}，{}}，{ShipmentEstimate”：{“货币代码”：“欧元”，“运费”：{“税费”：“1.7532”，“附加保险费用”：“0.00”，“运输费用”：“0.00”，“小计”：“1.7532”}，“产品代码”：{“5109.90.80.00”、“费用”：{“关税”：“75.0021”、“税费”：“0.00”、“增值税”：“0.00”、“货物成本”：“1250.00”、“小计”：“1325.0021”}，“产品汇总”：“1325.0021”}，“总计和成本”：“1326.7553”}，“抑制问题指标”：“Y”

如何仅获取TariffCode的值？

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结果必须是：5109.90.80.00unreadable@delboy1978uk请回答下面的问题

<?php

$json = '{"TransactionInfo":{"Date":"06\/04\/2018","Time":"09:29 ET","TransactionCharge":{"MonetaryValue":"0.00","CurrencyCode":{}}},"ShipmentEstimate":{"CurrencyCode":"EUR","ShipmentCharges":{"TaxesAndFees":"1.7532","AdditionalInsuranceCost":"0.00","TransportationCost":"0.00","SubTotal":"1.7532"},"ProductsCharges":{"Product":{"TariffCode":"5109.90.80.00","Charges":{"Duties":"75.0021","TaxesAndFees":"0.00","VAT":"0.00","CostOfGoods":"1250.00","SubTotal":"1325.0021"}},"ProductsSubTotal":"1325.0021"},"TotalLandedCost":"1326.7553"},"SuppressQuestionIndicator":"Y"}';
$array = json_decode($json, true);

echo $array['ShipmentEstimate']['ProductsCharges']['Product']['TariffCode'];