從基於關鍵字的固定長度的文本中提取字符串

Question

我嘗試過並嘗試過，但我很難過。假設我有以下情形：

$string = "Jenny's garden is one of the best in town, it has lush greens and colorful flowers. With what happened to her recently, she could use a new sprinkler system so that she does not have to over exert herself. Perhaps Joel can sell that extra bike to raise money or perhaps put up a garage sale."; 

$keyword = "recently"; 

$length = 136; 

// when keyword keyword is empty 
$result = "Jenny's garden is one of the best in town, it has lush greens and colorful flowers. With what happened to her recently, she could use a (snip)"; 

// when keyword is NOT empty 
$result = "(snip)it has lush greens and colorful flowers. With what happened to her recently, she could use a new sprinkler system so that she does not h(snip)"; 

我想要做的就是串的摘錄於$結果可能圍繞一個關鍵詞第一次出現（如果存在的話），如圖所示。我很困惑如何使用substr和strpos在php中實現這一點。幫幫我？

Answer 1

這應該對你所需要的工作：

if ($keyword != "") { 
    $strpos = strpos($string, $keyword); 
    $strStart = substr($string, $strpos - ($length/2), $length/2); 
    $strEnd = substr($string, $strpos + strlen($keyword), $length/2); 

    $result = $strStart . $keyword . $strEnd; 
} 
else { 
    $result = substr($string, 0, $length); 
} 

下面是測試代碼我使用：

<?PHP 
$string = "Jenny's garden is one of the best in town, it has lush greens and colorful flowers. With what happened to her recently, she could use a new sprinkler system so that she does not have to over exert herself. Perhaps Joel can sell that extra bike to raise money or perhaps put up a garage sale."; 

$keyword = "recently"; 

$length = 136; 

if ($keyword != "") { 
    $strpos = strpos($string, $keyword); 
    $strStart = substr($string, $strpos - ($length/2), $length/2); 
    $strEnd = substr($string, $strpos + strlen($keyword), $length/2); 

    $result = $strStart . $keyword . $strEnd; 
} 
else { 
    $result = substr($string, 0, $length); 
} 

echo $result; 
?> 

這裏是在呼應結果：

有鬱鬱蔥蔥的綠色和五顏六色的鮮花。隨着最近發生了什麼給她，她可以用一個新的自動噴水滅火系統，使她不必

編輯：修正了我的代碼一對夫婦的錯誤...

注：此選項將顯示一個$結果即136個字符+關鍵字的長度。如果你想要它只有136，添加$length = 136 - strlen($keyword);