Question

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Justifying Lines of Text</title>
<link rel="stylesheet" type="text/css" href="common.css" />
<style>
pre {font-family: Courier, monospace;}
</style>
</head>
<body>
<h1>Justifying Lines of Text</h1>

<?php

// The text to justify

$myText = <<<END_TEXT
But think not that this famous town has
only harpooneers, cannibals, and
bumpkins to show her visitors. Not at
all. Still New Bedford is a queer place.
Had it not been for us whalemen, that
tract of land would this day perhaps
have been in as howling condition as the
coast of Labrador.

END_TEXT;

$myText = str_replace( "\r\n", "\n", $myText );

$lineLength = 40; // The desired line length
$myTextJustified = "";
$numLines = substr_count( $myText, "\n" );
$startOfLine = 0;

// Move through each line in turn

for ( $i=0; $i < $numLines; $i++ ) {
  $originalLineLength = strpos( $myText, "\n", $startOfLine ) - $startOfLine;
  $justifiedLine = substr( $myText, $startOfLine, $originalLineLength );
  $justifiedLineLength = $originalLineLength;

  // Keep adding spaces between words until the desired
  // line length is reached

  while ( $i < $numLines - 1 && $justifiedLineLength < $lineLength ) {
    for ( $j=0; $j < $justifiedLineLength; $j++ ) {
      if ( $justifiedLineLength < $lineLength && $justifiedLine[$j] == " " ) {
        $justifiedLine = substr_replace( $justifiedLine, " ", $j, 0 );
        $justifiedLineLength++;
        $j++;
      }
    }
  }

  // Add the justified line to the string and move to the
  // start of the next line

  $myTextJustified .= "$justifiedLine\n";
  $startOfLine += $originalLineLength + 1;

本书对上述行的解释是“$ startOfLine指针被移动到开始下一行（将 1 添加到索引以跳过换行符）。

我的问题是：

新行字符“\ n”不应包含两个字符吗？为了跳过它，我们不应该将2添加到变量$ startOfLine而不是1？

让我们看一个简单的例子：

$myText = "Hello\nworld\n"

strpos ( $myText, "\n", 0); //Returns 5, which is also the length of the first line "Hello"
0+5+1; //Returns 6. It should be the index of the first character of the second line (w). But it's actually the index of the "n" right in front of it
strpos ( $myText, "\n", 6); //Returns 12
12-6   //Returns 6. This should be the length of the second line. But the second line actually contains 5 characters.

但如果我将1更改为2，脚本将无法正常工作。问题是什么？

}

?>

<h2>Original text:</h2>
<pre><?php echo $myText ?></pre>

<h2>Justified text:</h2>
<pre><?php echo $myTextJustified ?></pre>

</body>
</html>

Answer 1

我认为您正在寻找wordwrap()来证明文本的合理性。

<?php
$text = "The quick brown fox jumped over the lazy dog.";
$newtext = wordwrap($text, 20, "<br />\n");

echo $newtext;
?>

输出：

The quick brown fox<br />
jumped over the lazy<br />
dog.

将$ startOfLine指针移动到下一行的开头

1 个答案: