Ler cadeia Json / Array em Php
Eu tenho uma string que está no formato Json válido e se parece com isso:
{
"message": "success",
"result": {
"46620": {
"course_id": "29",
"en_title": "Google Analytics (Basic)",
"fa_title": "مبانی گوگل آنالیتیکز",
"badge_link": "http://www.darsnameh.com/badge/index.php?user=46620&badge="
},
"49449": {
"course_id": "16",
"en_title": "Multimedia Reporting 1- Reporting in the Internet Age",
"fa_title": "گزارش‌گری چندرسانه‌ای ۱- گزارشگری در زمانه‌ی اينترنت",
"badge_link": "http://www.darsnameh.com/badge/index.php?user=49449&badge="
},
"55480": {
"course_id": "33",
"en_title": "HTML for Journalists and Bloggers",
"fa_title": "آشنایی با اچ‌تی‌ام‌ال Ùˆ Ùناوری‌های اینترنت برای روزنامه‌نگاران Ùˆ وبلاگ‌نویس‌ها",
"badge_link": "http://www.darsnameh.com/badge/index.php?user=55480&badge="
},
"59250": {
"course_id": "31",
"en_title": "Twitter",
"fa_title": "توییتر",
"badge_link": "http://www.darsnameh.com/badge/index.php?user=59250&badge="
},
"103716": {
"course_id": "42",
"en_title": "How to write a CV?",
"fa_title": "چگونه رزومه بنویسیم؟",
"badge_link": "http://www.darsnameh.com/badge/index.php?user=103716&badge="
}
}
}
Eu quero ler campos diferentes, por exemplo, todos os fa_titles, eu uso $ obj = json_decode ($ str, true); para converter isso para Json, então echo sizeof ($ obj ['result']); mostra que tem 5 objetos de resultado, mas como posso acessar os campos fa_title ou en_title agora?