PHP sentence case function - php

Question

I have got a function from Google to clean my paragraph in sentence case.
I want to modify this function such that it converts more than 2 new line character to newline. Else it converts all new line characters in space. So I would have it in paragraph format. Here it's converting all new line character to space.
It's converting in proper sentence case. But, In case If I found single word having first word as capital then I need function to ignore that. As Sometimes, if there would be any noun It needs to be capital. We can't change it small case. Else if noun and it is having more than 2 capital characters other than first character than convert it to lower case.
Like -> Noun => Noun but NoUn => noun. Means I want if other than first character is capital than it convert it two lower case Else it keep it in same format.
function sentence_case($string) {
$sentences = preg_split('/([.?!]+)/', $string, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
$new_string = '';
foreach ($sentences as $key => $sentence) {
$new_string .= ($key & 1) == 0?
ucfirst(strtolower(trim($sentence))) :
$sentence.' ';
}
$new_string = preg_replace("/\bi\b/", "I", $new_string);
//$new_string = preg_replace("/\bi\'\b/", "I'", $new_string);
$new_string = clean_spaces($new_string);
$new_string = m_r_e_s($new_string);
return trim($new_string);
}

Answer 1

function sentence_case($str) {
$cap = true;
$ret='';
for($x = 0; $x < strlen($str); $x++){
$letter = substr($str, $x, 1);
if($letter == "." || $letter == "!" || $letter == "?"){
$cap = true;
}elseif($letter != " " && $cap == true){
$letter = strtoupper($letter);
$cap = false;
}
$ret .= $letter;
}
return $ret;
}
This will preserve existing proper noun capitals, acronyms and abbreviations.

Answer 2

This should do it:
function sentence_case($string) {
// Protect the paragraphs and the caps
$parDelim = "/(\n+\r?)/";
$string = preg_replace($parDelim, "#PAR#", $string);
$string = preg_replace("/\b([A-Z])/", "#$1#", $string);
$sentences = preg_split('/([.?!]+)/', $string, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
$new_string = '';
foreach ($sentences as $key => $sentence) {
$new_string .= ($key & 1) == 0?
ucfirst(strtolower(trim($sentence))) :
$sentence.' ';
}
$new_string = preg_replace("/\bi\b/", "I", $new_string);
//$new_string = preg_replace("/\bi\'\b/", "I'", $new_string);
$new_string = clean_spaces($new_string);
$new_string = m_r_e_s($new_string);
// Restore the paragraphs and the caps
$new_string = preg_replace("#PAR#", PHP_EOL, $new_string);
$new_string = preg_replace("/#([A-Z])#/", "$1", $new_string);
return trim($new_string);
}
It works by identifying the items you want to protect (paragraph & first cap) and marking it with a string that you can then replace back when you are done. The assumption is that you don't already have #PAR# and #A-Z# in the string. You can use whatever you want to use for the paragraph delimiter afterwards if you want to force a certain type of line ending or several lines in between.

Answer 3

Slightly modifying Sylverdrag's function, I got something that is working well for me. This version works for every messed-up sentence I've thrown at it so far :)
function sentence_case($string) {
$string = strtolower($string); // ADDED THIS LINE
// Protect the paragraphs and the caps
$parDelim = "/(\n+\r?)/";
$string = preg_replace($parDelim, "#PAR#", $string);
$string = preg_replace("/\b([A-Z])/", "#$1#", $string);
$sentences = preg_split('/([.?!]+)/', $string, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
$new_string = '';
foreach ($sentences as $key => $sentence) {
$new_string .= ($key & 1) == 0?
ucfirst(strtolower(trim($sentence))) :
$sentence.' ';
}
$new_string = preg_replace("/\bi\b/", "I", $new_string);
// GOT RID OF THESE LINES
// $new_string = preg_replace("/\bi\'\b/", "I'", $new_string);
// $new_string = clean_spaces($new_string);
// $new_string = m_r_e_s($new_string);
// Restore the paragraphs and the caps
$new_string = preg_replace("#PAR#", PHP_EOL, $new_string);
$new_string = preg_replace("/#([A-Z])#/", "$1", $new_string);
$new_string = preg_replace("/#([A-Z])#/", "$1", $new_string);
preg_match('/#(.*?)#/', $new_string, $match); // MODIFIED THIS LINE TO USE (.*?)
return trim($new_string);
}
$string = "that IS it!! YOU and i are Totally DONE hanging out toGether... like FOREveR DUDE! i AM serious. a good FRIEND would NOT treAT me LIKE you dO. it Seems, howEVER, THAT you ARE not ONE of tHe GOOD ONEs.";
echo "<b>String 1:</b> " . $string . "<br><b>String 2:</b> " . sentence_case($string);
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:) :)