使用PHP遍历JSON

Question

我无法弄清楚如何从下面的JSON获取以下键/值：

我需要在for循环中打印出：

“项目”，即“ test-project-1”

“数据集”，即“ dataset1”

“权限”，即“角色：作者，组：test1@test.com”

{
   "projects":{
      "test-project-1":{
         "datasets":{
            "dataset1":{
               "permissions":{
                  "role":"WRITER",
                  "group":"test1@test.com"
               }
            },
            "dataset2":{
               "permissions":{
                  "role":"READER",
                  "group":"test2@test.com"
               }
            },
            "dataset3":{
               "permissions":{
                  "role":"READER",
                  "group":"test3@test.com"
               }
            },
            "dataset4":{
               "permissions":{
                  "role":"READER",
                  "group":"test4@test.com"
               }
            },
            "dataset5":{
               "permissions":{
                  "role":"READER",
                  "group":"test5@test.com"
               }
            }
         }
      },
      "test-project-2":{
         "datasets":{
            "dataset1":{
               "permissions":{
                  "role":"WRITER",
                  "group":"test1@test.com"
               }
            },
            "dataset2":{
               "permissions":{
                  "role":"READER",
                  "group":"test2@test.com"
               }
            },
            "dataset3":{
               "permissions":{
                  "role":"READER",
                  "group":"test3@test.com"
               }
            },
            "dataset4":{
               "permissions":{
                  "role":"READER",
                  "group":"test4@test.com"
               }
            },
            "dataset5":{
               "permissions":{
                  "role":"READER",
                  "group":"test5@test.com"
               }
            }
         }
      }
   }
}

我试过了，但是唯一打印出来的是“ Array”。

这样的事情不起作用：

$new_json = {path_to_json};
$new_projects = $new_json['projects'];
foreach ($new_projects as $project) {
    echo $project . "<br>";
    foreach ($new_projects['datasets'] as $datasets){
        echo $datasets . "<br>";
    }
}

Answer 1

PHP代码演示

$json='{
   "projects":{
      "test-project-1":{
         "datasets":{
            "dataset1":{
               "permissions":{
                  "role":"WRITER",
                  "group":"test1@test.com"
               }
            },
            "dataset2":{
               "permissions":{
                  "role":"READER",
                  "group":"test2@test.com"
               }
            },
            "dataset3":{
               "permissions":{
                  "role":"READER",
                  "group":"test3@test.com"
               }
            },
            "dataset4":{
               "permissions":{
                  "role":"READER",
                  "group":"test4@test.com"
               }
            },
            "dataset5":{
               "permissions":{
                  "role":"READER",
                  "group":"test5@test.com"
               }
            }
         }
      },
      "test-project-2":{
         "datasets":{
            "dataset1":{
               "permissions":{
                  "role":"WRITER",
                  "group":"test1@test.com"
               }
            },
            "dataset2":{
               "permissions":{
                  "role":"READER",
                  "group":"test2@test.com"
               }
            },
            "dataset3":{
               "permissions":{
                  "role":"READER",
                  "group":"test3@test.com"
               }
            },
            "dataset4":{
               "permissions":{
                  "role":"READER",
                  "group":"test4@test.com"
               }
            },
            "dataset5":{
               "permissions":{
                  "role":"READER",
                  "group":"test5@test.com"
               }
            }
         }
      }
   }
}';
$array=  json_decode($json,true);
foreach($array["projects"] as $projectName => $projects)
{
    echo "Project name ".$projectName."<br/>";
    foreach($projects["datasets"] as $databaseNames => $databaseData)
    {
        echo "  Database name ".$databaseNames."<br/>";
        echo "  Database role ".$databaseData["permissions"]["role"]."<br/>";
        echo "  Database group ".$databaseData["permissions"]["group"]."<br/>";
    }
}

Answer 2

格式为foreach（“数组”为“数组中的键”）

foreach ($new_json as $new_projects) {
    echo $new_projects . "<br>";
    $datasets=$new_projects['datasets'];
    foreach ($new_projects as $datasets){
        echo $datasets . "<br>";
    }
}

Answer 3

您需要使用json_decode函数PHP手册

$jsonArray = json_decode($jsonData, true);
foreach($jsonArray as $project){
    echo $project . '<br>';
    foreach($project['datasets'] as $dataset)
    {
        echo $dataset . '<br>';
        foreach($dataset['permissions'] as $permissions)
        {
            echo sprintf('Role: %s, group: %s<br>', $permissions['role'], $permissions['group'];
        }
    }
}

如果您不希望将json转换为数组，则需要传递false作为第二个参数，而将返回stdClass。