problem in to create json

hi everybody

i new start work with codeigniter

i have problem in create and fillterin in json

i create json file but i can't strip_tags in json array

for example :

PHP Code:

$json = strip_tags($temp);
     

$GLOBALS['data'] .= str_replace('  ', ' ',$json); 


but in codeignter it dosent work ;

PHP Code:

$this->output->set_content_type('application/json')->set_output(json_encode($data)); 


sorry i can't good speak engilsh

these two snippets do 2 totally different things