CODEWITHSUNDEEP
c++string
Yevhen
Yevhen

Reputation: 1975

simple string question

If I assign a new value too previously declared string using operator= , is it freed automatically or I have to free it manually? 


std::string s("value_old");
s = "value_new";

what happens with "value_old" where I can find or where are you always watching to find answer to similar questions? Thanks in advance.

Upvotes: 2

Views: 134

Answers (5)

Buhake Sindi
Buhake Sindi

Reputation: 89189

The old value is freed and s becomes new_value.

From Source code std::string, The old value is erased (from erase() method) and new value is inserted and a reference string is returned. See assign() method.

Upvotes: 1

egrunin
egrunin

Reputation: 25083

Yes, it is freed automatically.

I suggest cplusplus.com for a handy online reference to STL.

Upvotes: 5

icecrime
icecrime

Reputation: 76825

The std::string manages the actual data and is responsible for memory management.

Where I can find or where are you always watching to find answer to similar questions?

For such questions, I would recommend a simple C++ book. A list is available on this post, but I think "The C++ Language" (Bjarne Stroustrup) would be a good choice to start with.

Upvotes: 1

sbi
sbi

Reputation: 224159

Generally: If you're using std::string you don't need to worry. It will take care of that.

In your concrete case: Very likely your std::string implementation will recycle the memory it had for "string_old", re-using it for "string_new".

Upvotes: 1

badgerr
badgerr

Reputation: 7982

std::string handles it's own memory, so when you use s = "value_new", the string "value_old" is sent to oblivion.

Upvotes: 8

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