Length of array of type String [duplicate]

Question

This question already has answers here:

How do I find the length of an array? (31 answers)

Closed 9 years ago.

I have :

string a[] = {"akdhska","asjd","askjdh"};

Is there any way to get the number of elements in this array?

As a resolution of this I am doing the following:

vector<string> a;
a.insert(a.end(),"test1"); // or a.push_back("test1")
a.insert(a.end(),"test");
a.insert(a.end(),"test12");
a.insert(a.end(),"test123");
int len = a.size();

• πάντα ῥεῖ: You can use sizeof(a)/sizeof(*a) as long you're in the same scope a was defined.
• juanchopanza: @πάνταῥεῖ Scope doesn't matter!
• Bo Persson: If you have a somewhat modern compiler, you can also do std::vector<std::string> a = {"akdhska","asjd","askjdh"};
• Bhumi Singhal: how does sizeof work for the String type? By default do we have a fixed siz for each string?
• juanchopanza: It isn't the string type that matters here, it is the length of the array.

Answer 1

A C++11 solution would be

std::size_t length = std::end(a) - std::begin(a);

or

std::size_t length = std::distance(std::begin(a), std::end(a));

Answer 2

You can probably use :

int length = sizeof(a)/sizeof(*a);

• Jacek Cz: best for compile-time known tables, 0 CPU use (at place when is born) BUT NOT when table is passed as argument
• juanchopanza: @JacekCz It depends how it is passed. I.e. what the type of the parameter of the function is.

Answer 3

string a[] = {"akdhska", "asjd", "askjdh"};
int len = sizeof(a) / sizeof(*a); // gives you number of elements

• Jacek Cz: best for compile-time known tables, 0 CPU use (at place when is born) BUT NOT when table is passed as argument