从 PHP 创建 JS 数组

Question

我正在开发 Google Geochart，我希望它是动态的。这是使数组存储两个值的静态代码如下。国家是地图的唯一标识符，颜色值是地图的颜色。（无关但上下文）  arrayData = [['Country','Color Value'],  ['China',3],  ['Russia',2.6],  ['France',2.5],  ['Spain',2.4],  ['Portugal',1.1]我希望能够从取自 php echo 值的 for 循环中创建此数组。像这样的伪代码；for (i in range table.length) arrayData = [['Country','Color Value'], [<?php echo $statements["Country"]; ?>], [<?php echo $statements["Color_Value"]; ?>], 与获取所有值的 php 表非常相似，我想做同样的事情，但对于 JavaScript 数组。任何建议都会很好！编辑：静态代码是一个例子，我想从数据库中获取值，第一个值是国家，第二个值是颜色值。两者都来自数据库。我想反过来使地理图表动态

Answer 1

您正在寻找的函数是json_encode()，但如果您首先构建输入数组，它会更有用。

所以像下面这样：

// Some code here to generate $arrayData from $statements, giving the following

$arrayData = [

  ['Country' => 'China', 'Color Value' => 3],

  ['Country' => 'Russia', 'Color Value' => 2.6],

  ['Country' => 'France', 'Color Value' => 2.5],

  ['Country' => 'Spain', 'Color Value' => 2.4],

  ['Country' => 'Portugal', 'Color Value' => 1.1]

];

// Then, once you have generated $arrayData

echo json_encode($arrayData);

Answer 2

您需要先在 php 中准备数组，而不仅仅是 echo json_encode($arr)：

<?php

$data = [];

foreach ($something as $statements) {

   $data[] = [$statements["Country"], $statements["Color_Value"]]; 

}

$arrayData = json_encode($data);

?>

arrayData = <?= $arrayData ?>;

Answer 3

//First you need to check the structure of the result from your database query

//Then Loop through the result Object/Array to get the desired structure

//Most Common way of doing this is foreach loop 

//define an blank array 

$chart = [];

//put your axis tags/ texts in on first index

$chart[] = ['Country', 'Colour Count'];

//let's say $reult stores the data fetched from database

foreach ($result as $key => $value){

    //let's assume $value has field with country name as value 

    //and field colour_count have color count values, so

    // $value->country = Country Name

    //$value->colour_count = Color Count Value

    $chart[] = [$value->country, $value->colour_count];

}

// Once the Loop is finished, you will get an array with your desired format

//$chart = [['Country', 'Colour Count'],['France', 12],['USA',34],.....so on];