Заменить «\», только если заключены "

Question

Я читаю строки из моей базы данных, для которой json_encode не работает. (С использованием PHP)

Мне нужно заменить все вхождения " с \", но только если возникновение уже включено "

Пример строки:.

{"val1": "This is "some value" that is inside of the "string" and such", "val2": "And here is yet another "value" that is messed up by quotation marks", "val3": "etc. etc."} 

Должен быть изменен на:

{"val1": "This is \"some value\" that is inside of the \"string\" and such", "val2": "And here is yet another \"value\" that is messed up by quotation marks", "val3": "etc. etc."} 

Answer 1

Попробуйте эту инструкцию:

В первый заменить " с \"

И заменить снова регулярное выражение следующим образом:

$a='{"val1": "This is "some value" that is inside of the "string" and such", "val2": "And here is yet another "value" that is messed up by quotation marks", "val3": "etc. etc."}'; 
var_dump($a); 
$a=str_replace('"','\"',$a); 
var_dump($a); 
$re = "~(\\\\\")([^\":]+)(\\\\\"):\\s*(\\\\\")([^,]+)(\\\\\")([,}])~m"; 
$str =$a; 
$subst = "\"$2\": \"$5\"$7"; 
$a=preg_replace($re, $subst, $str); 
var_dump($a); 

live demo

Выход:

string '{"val1": "This is "some value" that is inside of the "string" and such", "val2": "And here is yet another "value" that is messed up by quotation marks", "val3": "etc. etc."}' (length=173) 

string '{\"val1\": \"This is \"some value\" that is inside of the \"string\" and such\", \"val2\": \"And here is yet another \"value\" that is messed up by quotation marks\", \"val3\": \"etc. etc.\"}' (length=191) 

string '{"val1": "This is \"some value\" that is inside of the \"string\" and such", "val2": "And here is yet another \"value\" that is messed up by quotation marks", "val3": "etc. etc."}' (length=179)