php - 提取单词前后的部分字符串

Question

我需要提取并在查询词之前和之后显示一些词，比如谷歌搜索结果，例如:

$str = "hi user! welcome to new php open source world, we are trying to learn you something!";
$query = "new php";
$result = "... welcome to new php open source ...";

我搜索了 google 和 SO 但没有找到明确的答案，或者我的 php 知识还不够! 是否有可行且易于使用的功能来完成这项工作？

Answer 1

function yourFuncName($str, $query, $numOfWordToAdd) {
    list($before, $after) = explode($query, $str);

    $before = rtrim($before);
    $after  = ltrim($after);

    $beforeArray = array_reverse(explode(" ", $before));
    $afterArray  = explode(" ", $after);

    $countBeforeArray = count($beforeArray);
    $countAfterArray  = count($afterArray);

    $beforeString = "";
    if($countBeforeArray < $numOfWordToAdd) {
        $beforeString = implode(' ', $beforeArray);
    }
    else {
        for($i = 0; $i < $numOfWordToAdd; $i++) {
            $beforeString = $beforeArray[$i] . ' ' . $beforeString; 
        }
    }

    $afterString = "";
    if($countAfterArray < $numOfWordToAdd) {
        $afterString = implode(' ', $afterArray);
    }
    else {
        for($i = 0; $i < $numOfWordToAdd; $i++) {
            $afterString = $afterString . $afterArray[$i] . ' '; 
        }
    }

    $string = $beforeString . $query . ' ' . $afterString;

    return $string;
}

输出是: user!欢迎来到新的 php 开源世界， ($numOfWordToAdd = 3)