C++ Standard Library C++ STL Library

C++ <string> - max_size() Function

The C++ string::max_size function returns the maximum length the string can reach. The function returns the maximum potential length the string can reach due to known system or library implementation limitations.


size_type max_size() const;
size_type max_size() const noexcept;


No parameter is required.

Return Value

Maximum number of characters that can be held in a string.

Time Complexity

Constant i.e, Θ(1)


In the example below, the string::max_size function is used find out the maximum number of characters that a string can hold.

#include <iostream>
#include <string>

using namespace std;
int main (){
  string MyString = "Hello World!.";

  cout<<"Size of the String: "<<MyString.size()<<"\n";
  cout<<"Length of the String: "<<MyString.length()<<"\n";
  cout<<"Capacity of the String: "<<MyString.capacity()<<"\n";
  cout<<"Maximum size of the String: "<<MyString.max_size()<<"\n"; 
  return 0;

A possible output could be:

Size of the String: 13
Length of the String: 13
Capacity of the String: 15
Maximum size of the String: 9223372036854775807

❮ C++ <string> Library