无法使用foreach for google chart json打印多维数组

$data = [
    ['属性1', '属性2', '属性3'],
    [值1, 值2, 值3],
    [值4, 值5, 值6],
    // 更多数据点...
];

foreach ($data as $row) {
    foreach ($row as $value) {
        // 打印每个值
        echo $value;
    }
}

$chartData = [];
foreach ($data as $row) {
    $chartData[] = $row;
}
$chartJson = json_encode($chartData);

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
    google.charts.load('current', {'packages':['corechart']});
    google.charts.setOnLoadCallback(drawChart);

    function drawChart() {
        var data = google.visualization.arrayToDataTable(<?php echo $chartJson; ?>);

        // 创建图表并设置选项
        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        var options = {
            title: 'My Chart',
            // 更多选项...
        };

        // 绘制图表
        chart.draw(data, options);
    }
</script>