Question

如何将新数据添加到JSON结构？

以下是json.txt中的JSON：

[
 {"name":"foo","number":"1"},
 {"name":"bar","number":"2"},
 {"name":"Hello","number":"3"}
]

现在我想添加一个新行{"name":"good day","number":"**"}

$file = 'json.txt';
$data = json_decode(file_get_contents($file));
$newdata = array('name'=>'good day', 'number' => '**');// how to add `number` automatic `+1`, make it to `4` with php code?
$data[] = $newdata;
file_put_contents($file, json_encode($data));

Answer 1

$file = 'json.txt';
$data = json_decode(file_get_contents($file));
$newNumber = max(array_map(
   function($e) {return intval($e['number']);},
$data)) + 1;
$newdata = array('name'=>'good day', 'number' => strval($newNumber));
$data[] = $newdata;
file_put_contents($file, json_encode($data));

在php＆lt; 5.3，将$newNumber =语句替换为：

$newNumber = max(array_map(
    create_function('$e', 'return intval($e["number"]);'),
$data)) + 1;

Answer 2

在您的示例中，数字是连续的。为什么不使用end使号码自动增加？

<?php
$file = 'json.txt';
$data = json_decode(file_get_contents($file));
$number = (end($data)->number) + 1;
$newdata = array('name'=>'good day', 'number' => ''.$number.''); // how to add `number` automatic `+1`, make it to `4` with php code?
$data[] = $newdata;
file_put_contents($file, json_encode($data));
?>

php在json树中添加新数据

2 个答案: