Sentence case without regular expressions - php

Question

Is there a built-in php function, or a simple (efficient!) way to combine built-in functions, to give a string sentence case ("Sentence one. Sentence two.")?
PHP has similar built-in functions, but none that I can find for my it to my purposes:
ucfirst(strtolower("SENTENCE ONE. AND HERE'S TWO.")) returns "Sentence one. and here's two."; ucwords(strtolower("SENTENCE ONE. AND HERE'S TWO.")) "Sentence One. And Here's Two."

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

You could split the string on ".", then ucfirst each sentence. Not the most elegant solution, but it works.
$sentences = explode(".",$paragraph);
$text = "";
foreach($sentences as $sentence) {
$text .= ucfirst(strtolower($sentence)).".";
}

Answer 3

Try this:
function sentenceCase($s){
$str = strtolower($s);
$cap = true;
for($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;
}
Taken from php.net Works with more than just periods as line endings.

Answer 4

I came up with this solution using preg_split. It will try to split sentences on . boundaries where there is one or more spaces after the period.
It is still pretty efficient, but arguably less so that it's explode counterpart.
<?php
$str = "SENTENCE ONE. AND HERE'S TWO.";
$sentences = preg_split('/(\.\s+)/', $str, null, PREG_SPLIT_DELIM_CAPTURE);
array_walk(&$sentences, create_function('&$val', '$val = ucfirst(strtolower($val));'));
$str = implode('', $sentences);
echo $str; // Sentence one. And here's two.

Answer 5

Will work with new line breaks not only spaces.
function sentenceCase($text){
$cap = true; $newText = '';
for($x = 0; $x < strlen($text); $x++){
$letter = substr($text, $x, 1);
if($letter == '.' || $letter == '!' || $letter == '?' || $letter == "\n"){
$cap = true;
} elseif($letter != ' ' && $cap == true){
$letter = strtoupper($letter);
$cap = false;
}
$newText .= $letter;
}
return $newText;
}