Confused about literal and class method

[csstudent123]

In Javascript you can get substring "string".method(x,y);

how come I get this in C++ by passing a literal but not an object?

in C i do this

class s {

private:
char[2];
public:
int subs(char[]);
};

int s::subs(char ch[]){
//loop
//i++;
return i;//as substring length
}

[mutexe]

easiest/laziest way would be to initialise a std::string passing in your string literal to the constructor then just call size() on that. wrap it in a function:

#include <iostream>
#include <string>

size_t GetLength(const char array[])
{
	std::string fooString(array);
	return fooString.size();
}

int main()
{
	std::cout << "Length: " << GetLength("Foo") << std::endl;
	return 0;
}

[csstudent123]

How? when I initialise I must initialise a var, but I want to pass a literal as JS

"Hello".len(); //in c++

[mutexe]

I updated post with an example.

I don't see the point of this:

"Hello".len();

it's a literal so you know the length at compile time?
Why not just use 5 in it's place?

[csstudent123]

Just want to know if its possible in c/c++, because I want to know the technique how you compute something without making an object for it

[csstudent123]

I am guessing, its the job of compiler to do something like this...

[mutexe]

Just want to know if its possible in c/c++
No.

[MiiNiPaa]

You can call methods on string literals using C++14: http://coliru.stacked-crooked.com/a/6b6a2e5266cff783

[mutexe]

I stand corrected :)

[csstudent123]

So its implemented by compiler correct? :)
And c++14 is not standard yet, correct?

[MiiNiPaa]

Ib both javascript and c++ this will create an object and immideatly destroy it. In C++ this should be remembered if you want to get pointer/reference to object/its internals.

If you want to avoid runtime expenses, you should look into constexpr functions which works neatly with string literals.

[csstudent123]

got it now


Year C++ Standard Informal name
1998 ISO/IEC 14882:1998[12] C++98
2003 ISO/IEC 14882:2003[13] C++03
2007 ISO/IEC TR 19768:2007[14] C++TR1
2011 ISO/IEC 14882:2011[4] C++11
2014 N3690 (working draft C++14)[15] C++14
2017 to be determined C++17
wiki

[csstudent123]

Ib both javascript and c++ this will create an object and immideatly destroy it.

This is NOT programmers job, but compilers?

[MiiNiPaa]

C++14 was standartised in August. It is already 5 month standard.
Yes. it is a syntax sugar. s at the end of string literal converts it to the std::string

[csstudent123]

Thanks everyone