有人可以向我解释这个 'counting sentences' php 代码吗？

Question

我有一个不使用str_word_count来数句子的任务，学长给我的，我看不懂。有人可以解释一下吗？

我需要了解变量及其工作原理。

<?php

$sentences = "this book are bigger than encyclopedia";

function countSentences($sentences) {
    $y = "";
    $numberOfSentences = 0;
    $index = 0;

    while($sentences != $y) {
        $y .= $sentences[$index];
        if ($sentences[$index] == " ") {
            $numberOfSentences++;
        }
        $index++;
    }
    $numberOfSentences++;
    return $numberOfSentences;
}

echo countSentences($sentences);

?>

输出为

6

Answer 1

基本上就是统计一个句子中space的个数

<?php

  $sentences = "this book are bigger than encyclopedia";

  function countSentences($sentences) {
    $y = ""; // Temporary variable used to reach all chars in $sentences during the loop
    $numberOfSentences = 0; // Counter of words
    $index = 0; // Array index used for $sentences

    // Reach all chars from $sentences (char by char)
    while($sentences != $y) {
      $y .= $sentences[$index]; // Adding the current char in $y

      // If current char is a space, we increase the counter of word
      if ($sentences[$index] == " "){
        $numberOfSentences++;
      }

      $index++; // Increment the index used with $sentences in order to reach the next char in the next loop round
    }

    $numberOfSentences++; // Additional incrementation to count the last word
    return $numberOfSentences;
  }

  echo countSentences($sentences);

?>

请注意，此函数在某些情况下会产生错误结果，例如，如果后面有两个 space，此函数将计算 2 个单词而不是一个。

Answer 2

我会说这是非常微不足道的事情。任务是计算句子中的单词。句子是一个字符串（字符序列），是字母或白色spaces（space，换行等）...

现在，句子中的一个词是什么？ "don't touch" 另一组字母是一组不同的字母；意思是单词（一组字母）用白色 space 相互分隔（假设只是一个普通的空白 space）

所以最简单的单词计数算法包括： - $words_count_variable = 0 - 逐个检查所有角色 - 每次你找到一个space，这意味着一个新词刚刚结束，你必须增加你的$words_count_variable - 最后，您会找到字符串的末尾，这意味着在此之前刚刚结束的一个词，因此您将最后一次增加 $words_count_variable

取"this is a sentence".

We set $words_count_variable = 0;

Your while cycle will analyze:
"t"
"h"
"i"
"s"
" " -> blank space: a word just ended -> $words_count_variable++ (becomes 1)
"i"
"s"
" " -> blank space: a word just ended -> $words_count_variable++ (becomes 2)
"a"
" " -> blank space: a word just ended -> $words_count_variable++ (becomes 3)
"s"
"e"
"n"
...
"n"
"c"
"e"
-> end reached: a word just ended -> $words_count_variable++ (becomes 4)

那么，4。共计 4 个字。

希望这对您有所帮助。

有人可以向我解释这个 'counting sentences' php 代码吗？

Can someone explain to me this 'counting sentences' php code?

php

string

count

word-count