$a = <<<EOF 
thy38 
csdn 
blog 
EOF;

var c='thy38\n\ 
csdn\n\ 
blog';

var b=JSON.parse(<?php echo '\''.json_encode(explode("\r\n", $a)).'\''; ?>).join('\n'); 
alert(b==c); 

<input type="hidden" id='testphp' value="<?php echo $a?>" /> 
var a=document.getElementById("testphp").value; 
var b=JSON.parse(<?php echo '\''.json_encode(explode("\r\n", $a)).'\''; ?>).join('\n'); 
alert(a==b); 
alert(b==c); 

var d=<?php echo '\''.str_replace("\r\n", "\\n\\\n", $a).'\''; ?>; 
alert(d==c);