到目前为止，所有的答案似乎都做了大量不必要的工作、strlen计算、字符串分配（substr）等。“strpos”和“stripos”函数返回$haystack中$needle第一次出现的索引：

function startsWith($haystack,$needle,$case=true)
{
    if ($case)
        return strpos($haystack, $needle, 0) === 0;

    return stripos($haystack, $needle, 0) === 0;
}

function endsWith($haystack,$needle,$case=true)
{
    $expectedPosition = strlen($haystack) - strlen($needle);

    if ($case)
        return strrpos($haystack, $needle, 0) === $expectedPosition;

    return strripos($haystack, $needle, 0) === $expectedPosition;
}

如果速度对你很重要，试试这个。（我认为这是最快的方法）

仅适用于字符串，如果$haystack只有1个字符

function startsWithChar($needle, $haystack)
{
   return ($needle === $haystack[0]);
}

function endsWithChar($needle, $haystack)
{
   return ($needle === $haystack[strlen($haystack) - 1]);
}

$str='|apples}';
echo startsWithChar('|',$str); //Returns true
echo endsWithChar('}',$str); //Returns true
echo startsWithChar('=',$str); //Returns false
echo endsWithChar('#',$str); //Returns false

这可能奏效

function startsWith($haystack, $needle) {
     return substr($haystack, 0, strlen($needle)) == $needle;
}

资料来源：https://stackoverflow.com/a/4419658

这里有两个函数不会引入临时字符串，这在针头很大时可能很有用：

function startsWith($haystack, $needle)
{
    return strncmp($haystack, $needle, strlen($needle)) === 0;
}

function endsWith($haystack, $needle)
{
    return $needle === '' || substr_compare($haystack, $needle, -strlen($needle)) === 0;
}

到目前为止，所有的答案似乎都做了大量不必要的工作、strlen计算、字符串分配（substr）等。“strpos”和“stripos”函数返回$haystack中$needle第一次出现的索引：

function startsWith($haystack,$needle,$case=true)
{
    if ($case)
        return strpos($haystack, $needle, 0) === 0;

    return stripos($haystack, $needle, 0) === 0;
}

function endsWith($haystack,$needle,$case=true)
{
    $expectedPosition = strlen($haystack) - strlen($needle);

    if ($case)
        return strrpos($haystack, $needle, 0) === $expectedPosition;

    return strripos($haystack, $needle, 0) === $expectedPosition;
}

我希望以下答案既有效又简单：

$content = "The main string to search";
$search = "T";
//For compare the begining string with case insensitive. 
if(stripos($content, $search) === 0) echo 'Yes';
else echo 'No';

//For compare the begining string with case sensitive. 
if(strpos($content, $search) === 0) echo 'Yes';
else echo 'No';

//For compare the ending string with case insensitive. 
if(stripos(strrev($content), strrev($search)) === 0) echo 'Yes';
else echo 'No';

//For compare the ending string with case sensitive. 
if(strpos(strrev($content), strrev($search)) === 0) echo 'Yes';
else echo 'No';