I want to learn c++ language but I do not understand from where will I start from?
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The best way to learn C++ is to pick up a book and a compiler to implement it on. Although today there are online compilers too,where you can compile and run your code. So, I will discuss about it later, first it's important what book or what course you follow.
Between a course and a book , I will suggest a book for learning C++ ,as a course can not teach you the indepth details of the language as the book can. There are a lot of books available to go through ,but the best I suppose is C++:The Complete reference by Herbert Schildt. The online PDF is available on various sites. The language is good, easy to understand and covers each and every concept in a proper order. Make sure you do have a look.