Question

今天我使用PHP DOMDocument类来查找源代码中的所有链接。 $ links数组包含来自网站的所有链接。函数'for'使用循环迭代查找给定$ domain。

<div class="wrapper" ng-click="$event.stopPropagation()" style="width: 100%; height: 300px; background:grey;">
<div class="btn-group" uib-dropdown>
  <button id="split-button" type="button" class="btn btn-danger">Action</button>
  <button type="button" class="btn btn-danger" uib-dropdown-toggle>
    <span class="caret"></span>
    <span class="sr-only">Split button!</span>
  </button>
  <ul class="dropdown-menu" uib-dropdown-menu role="menu" aria-labelledby="split-button">
    <li role="menuitem"><a href="#">Action</a></li>
    <li role="menuitem"><a href="#">Another action</a></li>
    <li role="menuitem"><a href="#">Something else here</a></li>
    <li class="divider"></li>
    <li role="menuitem"><a href="#">Separated link</a></li>
  </ul>
</div>

示例：

搜索域名：http：//example.com 搜索网址：http：//www.iana.org

结果：

echo 'Find link: ' . $domain . '';
echo "<b>Status: ";

//$links is array with all links
//$domain is domain for example : http://example.com

for($i = 0;$i<count($links);$i++)
        {
            $find_href = preg_match("@$domain@i", $links[$i]['href']);

            if($find_href)
            {

                    if($links[$i]['href'] != "")
                    {
                        echo $links[$i]['anchor'];
                        echo 'Link found';'
                    }
                    else
                    {
                        echo 'Link not found';
                    }

搜索域名：http://example.com 搜索链接：http://google.com

结果：

Link not found
Link not found
Link not found
Link not found
Link not found
http://www.iana.org/domains/example
Link found  // find bacouse link is in source code of http://example.com
Link not found
Link not found
Link not found
Link not found
Link not found
Link not found
Link not found

如果在$ links数组中找不到$ domain，如何打印一次“链接未找到”？

Answer 1

每次for循环使用变量'$ i'执行+ 1。创建一个变量'$ total'并计算'$ links'，然后在for循环中执行：

<!-- above the for loop -->
$total = count($links);  

<!-- in the for loop -->
if ($i == $total) {
    echo 'Link not found';
}

Answer 2

只需在变量中注册找到的条件，然后根据您是否找到某些内容，在循环完成后输出未找到的消息。

echo 'Find link: ' . $domain . '';
echo "<b>Status: ";

//$links is array with all links
//$domain is domain for example : http://example.com

$found = false;

for($i = 0;$i<count($links);$i++) {
    $find_href = preg_match("@$domain@i", $links[$i]['href']);

    if($find_href) {

        if($links[$i]['href'] != "") {
            echo $links[$i]['anchor'];
            echo 'Link found';
            $found = true;
        }
    }
}
if (!$found) {
    echo 'Link not found';
}

接收收到的评论这将是更好的代码

echo 'Find link: ' . $domain . '';
echo "<b>Status: ";

//$links is array with all links
//$domain is domain for example : http://example.com

$found = false;

foreach ($links as $link) {
    $find_href = preg_match("@$domain@i", $link['href']);

    if($find_href) {
        if($link['href'] != '') {
            echo $link['anchor'] . "\nLink found";
            $found = true;
        }
    }
}
if (!$found) {
    echo 'Link not found';
}

PHP - 在for循环中显示'echo'一次

2 个答案: