如果匹配输出匹配行后面的值，则foreach中的php校验值

Question

一些简单的代码，如果我有一个json数据的话。我想做一些事情，首先检查json数据中的match string，如果有，输出匹配线之后的值，否则输出所有的json数据。

Exapmle 1，匹配字符串为9，匹配json数据，输出匹配行7，3之后的值。

$txt = '[{"a":"5"},{"a":"9"},{"a":"7"},{"a":"3"}]';
$array = json_decode($txt);
$match_string = '9';
foreach ($array as $data){      
    echo $data->a;//7, 3
}

示例2，匹配字符串为2，在json数据中不匹配，输出所有值5，9，7，3。

$txt = '[{"a":"5"},{"a":"9"},{"a":"7"},{"a":"3"}]';
$array = json_decode($txt);
$match_string = '2';
foreach ($array as $data){      
    echo $data->a;//5, 9, 7, 3
}

该如何判断呢？我在foreach中做了一些类似的事情，只是忽略匹配字符串：

if($match_string == $data->a){
  continue;//fut this in the foreach ,get 5, 7, 3, but I need 7, 3, next value from 9.
}

谢谢。

Answer 1

您需要设置一个标志，告诉您是否找到了匹配项：

$txt = '[{"a":"5"},{"a":"9"},{"a":"7"},{"a":"3"}]';
$array = json_decode($txt);
$match_string = "2";
$found = false;
foreach ($array as $data) {
    if ($found) {
        echo $data->a;
    } else if ($data->a === $match_string) {
        // If we set $found *after* we have the opportunity to display it,
        // we'll have to wait until the next pass.
        $found = true;
    }
}
if (!$found) {
    // Display everything
    foreach ($array as $data) {
        echo $data->a;
    }
}

Answer 2

让它变得更短。

$txt = '[{"a":"5"},{"a":"9"},{"a":"7"},{"a":"3"}]';
$array = json_decode($txt);
$toFind = "9";
$mapped = array_map("current",$array);

if (!in_array($toFind,$mapped))
    echo implode(", ",$mapped);
else
    echo implode(", ",array_slice($mapped,array_search($toFind,$mapped)+1));

请注意，您不会使用该函数保留键

为性能而编辑

Answer 3

$matched = false;
foreach($array as $data){
    if($matched)
        echo $data->a;
    $matched = ($data->a==$matchString) || $matched;
}
if(!$matched)
    foreach($array as $data)
        echo $data->a;

这是你的基本情况。