Tutorial on using static_PHP in php functions

function sendHeader($num, $rtarr = null) {
​ static $sapi = null;
If ($sapi === null) {
          $sapi = php_sapi_name();
}
Return $sapi++;
When looking at the PW source code, I found that the static keyword is used in the setHeader() function, which is very strange. It has never been used in this way before.
Static is used in functions. After a variable is declared once, if the function is called again, the initial value will be continued. For example, $sapi will be accumulated.

echo sendHeader(1)."
";
echo sendHeader(2)."
";
echo sendHeader(3)."
";
Output:

apache2handler
apache2handles
apache2handlet
It is similar to global, but the difference is the scope. static can only be used on this function.
Interesting. Needs further research.

Excerpted from zaric

http://www.bkjia.com/PHPjc/478180.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/478180.htmlTechArticlefunction sendHeader($num, $rtarr = null) { static $sapi = null; if ($sapi == = null) { $sapi = php_sapi_name(); } return $sapi++; When looking at the PW source code, I found that the setHeader() function uses...