php - 仅当它在自己的行上时才删除术语

Question

我有这个:

$text = '
   hello world
    
    hello
';

如何删除   只有如果它在自己的线上？所以在上面的例子中，第二个  应该被删除。结果应该是:

$text = '
   hello world

    hello
';

到目前为止我尝试过的

通过 str_replace() ， 我可以:

$text = str_replace(' ', '', $text);

但这将删除   的所有实例，不仅是在它自己的线路上。

Answer 1

我已经尝试过这种方法，我得到了你想要的输出

// Your initial text
$text = '
   hello world
    
    hello
';

// Explode the text on each new line and get an array with all lines of the text
$lines = explode("\n", $text);

// Iterrate over all the available lines
foreach($lines as $idx => $line) {
    // Here you are free to do any if statement you want, that helps to filter
    // your text.

    // Make sure that the text doesn't have any spaces before or after and 
    // check if the text in the given line is exactly the same is the  
    if ( ' ' === trim($line) ) {
        // If the text in the given line is   then replace this line 
        // with and emty character
        $lines[$idx] = str_replace(' ', '', $lines[$idx]);
    }
}

// Finally implode all the lines in a new text seperated by new lines.
echo implode("\n", $lines);

我在本地的输出是这样的:

hello world

 hello