How to solve the problem that the n newline character in the php string is invalid and cannot be broken?

There is the following php code:

echo 'hellon';
echo 'world';
?>

The newline character n in the program will be output directly, and the newline cannot be changed correctly. Solution Method: Change single quotes to double quotes:

echo "hellon";
echo "world";
?>

In fact, it is the difference between double quotes and single quotes in php, a simple summary Variables in double quotes can be parsed, and single quotes are absolute strings. Example, three ways to remove line breaks in PHP

//php Line breaks in different systems
//The implementation of line breaks in different systems is different
///n is used in linux and unix
// mac uses /r
//window to reflect the difference from linux, it is /r/n
//so the implementation methods are different on different platforms
//php There are three methods to solve
$str = str_replace(array("/r/n", "/r", "/n"), "", $str);
< ;p>//2. Use regular replacement
$str = preg_replace('//s*/', '', $str);
//3. Use PHP to define it Variables (recommended)
$str = str_replace(php_eol, '', $str);
?>